The confusing and contradictory responses by Latin America experts who participated in our survey call attention to potentially misleading policies that might be fomented by erroneous perceptions and weak indicators.

Almost 30 years ago, Amalia Reátegui and her husband, Eusebio, packed up their possessions, wrestled together their eight children, and moved to their new home: a dusty plot of land on the barren outskirts of the Peruvian capital, Lima. At first, life wasn’t easy there. Basic services, like running water and electricity, weren’t available. Roads were unpaved, and public transportation was nonexistent. Quality schools and health clinics were far away, in the more established and wealthier neighborhoods.

But even though conditions were tough, moving to San Juan de Lurigancho, one of Lima’s earliest informal settlements, offered the couple a rare chance to become homeowners, which would have been out of their reach in the city’s traditional districts.

Little by little, things improved. They built a sturdy house made of concrete, got electricity and, years later, running water and sewage. Buses arrived, and even a metro connecting San Juan de Lurigancho to the rest of the city. Their children went off to postsecondary education, and later landed jobs in hospitals, the municipality, and the navy.

Just as important for Amalia and Eusebio was a piece of paper from the government—the title recognizing their formal ownership of the 120-square-meter plot of land where they lived.

Today, the couple still lives in the same peach-colored house, but their family home, like their neighborhood, has been transformed over the years. The one-story house is now a four-story building with eight two-bedroom apartments, one for each of their adult children.

For Amalia, a 71-year-old soft-spoken grandmother with shoulder-length black hair, this was all part of the plan. “When we first built our home, I always thought it would be for my children,” she said. “It is my house, and it is for them.”

But for her children, who spent the equivalent of tens-of-thousands of dollars to build the upper floors, the current living situation leaves them in a legal limbo, where the ownership of their apartments is based solely on a verbal agreement with their parents rather than legal paperwork.

Reverting to Informality

The case highlights a new trend that is puzzling experts of urban development and property rights in Peru. After years of demanding legal titles for their homes, residents are allowing their properties to become deregularized by failing to use the national registry, known as Sunarp, to document property transactions such as real estate sales, change of ownership within families, or the construction of additional floors subdivided into apartments. As a result, properties revert to informality, and the government registry does not accurately reflect the actual owners.

The issue is a growing concern for policy experts, who say it could have major social, economic, and legal costs. Without legal registration, disputes can quickly arise among siblings over ownership of a family home after the parents die. Resolving the dispute can lead to high legal costs in Peru’s already overburdened and slow courts. Informal owners can’t use their property as collateral for formal bank financing, and they face lower resale value if they decide to put their home on the market. It also risks undermining the sustainability of Peru’s pioneering titling program, a popular tool aimed at promoting economic development that was later emulated around the world.

“The children are now living in the same situation that their parents were living in 40 years ago. They’ve become informal again,” said Julio Calderón, a Peruvian sociologist, Lincoln Institute researcher, and expert on property rights. “Urbanistically, this is a time bomb.”

The Rise of Informal Settlements in Peru

Like other Latin American capitals, Lima experienced a population explosion during the second half of the last century, as migrants from across Peru flooded into the arid coastal city seeking a better life.

In 1950, fewer than a million people lived in Lima. By 2000, that number had ballooned to 7.4 million, according to the United Nations Population Division. Today, the Peruvian capital is home to more than 9 million people, representing almost a third of the country’s total population. The drivers of Peru’s internal migration are varied, but it’s mainly a result of political and economic hardships in the countryside. In the 1970s, the rural economy crashed following a failed agrarian reform by General Juan Velasco, a leftwing military dictator.

The economy was battered again in the early 1980s during one of the worst El Niño weather events on record, causing damaging floods and collapse of the fisheries. At around the same time, the leftist Shining Path rebels launched a violent insurgency in the southern highlands, forcing many residents there to flee to Lima to escape a bloody conflict that would claim about 70,000 lives.

In Lima, the government wasn’t prepared for the wave of migrants. With nowhere to live, new residents began to take over vacant land on the city’s outskirts, sometimes clashing with police. One of those informal developments eventually became San Juan de Lurigancho. Hector Nicho, a community leader there, remembers the authorities as being powerless to stop the flood of people who seized land, hoping to make it their own.

“The first day of the invasion, there were 15 or 20 people. The following day, we were 500. The day after that, we were 1,500. It just kept growing. They couldn’t stop it, even though the state had sent police,” said Nicho, who was just a boy when he participated in the land invasion some four decades ago.

Land grabs occurred throughout Lima, eventually leading to the creation of districts like Villa El Salvador on the city’s southern edge and San Martin de Porres in the north. The squatters were some of the city’s most impoverished residents, living in areas noticeable for the lack of state presence and vast informal economy.

By the late 1980s, things were only getting worse. Peru’s economy had spiraled into hyperinflation. The Shining Path, once confined to the rural highlands, was fast encroaching on Lima, threatening to overthrow the government and install a Maoist-inspired regime.

De Soto’s Titling Program

Around this time, Hernando de Soto, a Peruvian economist, proposed a way out of the mess. De Soto argued that providing legal ownership to property would trigger development by allowing the poor to leverage their individual assets in the formal economy and access financing. But complex and expensive bureaucratic barriers were preventing that from happening, De Soto said.

“They realized that one of the biggest obstacles to registering property in Peru was their own public registry,” said Angel Ayala, a lawyer and expert on property registration. “The problem wasn’t the informality. The problem was that the formal sector wouldn’t allow you to enter it,” he said, referring to the government’s then-complex and costly regulations for property registration.

De Soto’s ideas were embraced by Peru, which created a new legal framework to provide property titles for people like the Reáteguis, living in informal settlements in places like San Juan de Lurigancho.

In 1996, the government created the Commission for the Official Registration of Informal Property (COFOPRI) to lead a nationwide urban titling program. It also created a parallel registry, known in Spanish as the Registro Predial Urbano. The registry, which focused only on Lima’s informal settlements, slashed the requirements for property registration, making it faster and cheaper for poor land owners to get titles.

The results were impressive. According to Regularization of Informal Settlements in Latin America, a Lincoln Institute report by Brazilian lawyer Edésio Fernandes, COFOPRI reduced the time to obtain a title from 7 years to 45 days. It cut the number of steps from 2,007 to 4. The cost of registering declined from US$2,156 to almost nothing.

Since its creation, COFOPRI has issued about two million property titles, making it one of the largest programs of its kind in the world.

“The people who worked there worked 24 hours a day,” said Jorge Ortiz, a former COFOPRI employee who later became the superintendent of Peru’s traditional public registry, known as Sunarp. “They really identified with what they were doing.”

De Soto’s titling policy became the preeminent approach for land regularization around the world. It won praise from development organizations like the World Bank and the Inter-American Development Bank, and from politicians like former U.S. President Bill Clinton. Peru, as a pioneer of the program, became a model for other countries in Latin America, Africa, and Asia that were also grappling with widespread informality and poverty.

Almost 20 years since the creation of COFOPRI, academics have identified several social and economic benefits from titling. Families with formal title, for example, invest more in their homes and their children’s education, studies show. They also have fewer children.

Critics of the program, however, argue that De Soto’s main hypothesis—that titles will increase the poor’s access to formal credit—has simply not materialized as he envisioned.

They also point to unintended consequences of large land-titling programs, such as political manipulation and incentive for squatters to continue invading land, creating new informal developments without services, in the hope of being registered one day.

The Risks of Deregularization

In Peru, one of the main concerns is the sustainability of the titling, as more and more properties are becoming deregularized. Years after they seized land, the original property owners are retiring or passing away. Their property, often given to their children, is slipping back into informality.

“What we have seen happening is that the second and third property transactions are no longer registered. For a number of reasons, people simply fail to keep their properties fully legal,” said Fernandes. “So in a few years’ time, you are back to square one in terms of the legalities of the area.”

Unless the trend changes, policy experts say, the government’s aggressive titling program could unravel, along with its benefits.

Informal property owners risk losing the most basic benefit of titling: tenure security and legal protection against eviction and fraud. They could face other costs, like legal expenditures to resolve disputes over ownership.

There are also opportunity costs. Informal homeowners can’t use their property to access formal credit. They’d also miss out on receiving fair market compensation if they decided to sell their home.

The extent of the deregularization is difficult to gauge, but a recent Lincoln Institute study by Oswaldo Molina, an Oxford-trained economist, found that just 21 percent of second property transactions in Peru’s recently titled areas were being formally registered (Molina 2014).

“When the reform started, it wasn’t just an issue of providing titles to the people, but maintaining them formal,” said Molina. “So what happened with the other 79 percent?”

“We are now going to have numerous properties with titles, but in the name of someone else,” he added.

Causes for the Failure to Register

During his time as the head of Sunarp, Ortiz said it was extremely rare to see individuals registering second property transactions. For Ortiz, this has been a disappointment.

“I believed in the model from the 1990s,” said Ortiz, who was the head of Sunarp during the start of President Ollanta Humala’s administration in 2011. “And now, some 30 years later, I’m seeing that it could go to waste.”

The causes of deregularization are obscure, but experts point to cultural issues and changes in public policy as important drivers.

In many places in Peru, there is a strong respect for the verbal decisions of parents, even concerning important legal issues like property registration. In cases where a family home is subdivided, children rely on their parents, the property owners, to sign off on the transaction in order to provide them with a formal title.

Experts say that many parents are happy to let their children pay for the subdivision, but they don’t consider providing formal title, believing that a verbal agreement is sufficient to split up the property. In other cases, parents refuse to provide title over concerns that they could lose control over their home.

“There is still a culture where you respect the decision and the word of the parents,” said Jesus Quispe, the director of Cenca, a Lima-based urban development institute, which works in San Juan de Lurigancho. “Few transactions go through the legal system. There is a culture of informality.”

Ramiro García, the head of the urban program at the Peruvian development organization Desco, says many families ignore the public registry until they confront a problem, like a legal dispute over ownership.

“It is bureaucratic, expensive, and families don’t consider it necessary,” he said from his office in Villa El Salvador.

Before Lima’s population boom, families that couldn’t afford to buy a home could move to the outskirts, grab a piece of land, and build a house. Today, most of the vacant land is gone. What remains is located on the edge of mountains, often unstable for living.

As land has become scarcer, demand for housing has remained robust. As a result, the city has started to expand upward, with apartment buildings replacing houses.

Real estate prices have also skyrocketed, driven by Peru’s strong economic growth over the past decade. For young families from lower-middle class backgrounds, escalating costs have made it increasingly difficult to acquire their first home.

To help their children, parents who settled Lima’s outskirts a few decades ago are now adding two or three floors to their homes, and subdividing them into apartments.

In San Juan de Lurigancho, Melly Rosas, a 53-year-old secretary at a church, decided to add three more floors to her house after watching her married children struggle to save up enough money to buy a property.

“At first, this wasn’t our plan,” she said. “But it was too expensive for them to buy land while paying rent.”

“We are growing upward because there isn’t any more space,” Rosas added, referring to the increasing number of buildings in her neighborhood.

Rosas and her husband, Ricardo, haven’t looked into providing titles for their children’s apartments, but they plan to. “We know we have to do so, because it will reduce a lot of problems they could have,” she said. “Right now, everything is verbal.”

A short drive away, on a quiet, residential street, Marcelo Nuñez, a 52-year-old shoemaker, lives in a spacious house with high ceilings that help to keep it cool during Lima’s hot summer days. Attached to the house is a small store, where his wife sells soft drinks and potato chips.

Like their neighbors, Nuñez and his family slowly built their home over the last 30 years, one wall at a time. Now his 28-year-old daughter is building a second floor, where she plans to live with her baby boy. Nuñez’s son, 25, will likely live on the third floor.

Nuñez said he hadn’t planned to register the upper floors, even though they will be owned by his children. “For my part, I hadn’t thought about doing it legally, because we are family,” he said. “It’s pretty strange to do a subdivision legally. Normally it is just by word.”

But, like Rosas, Nuñez agrees that leaving his children without formal titles could create future problems. “If they’re in agreement, I wouldn’t have a problem with doing it legally,” he said.

But cultural factors aren’t the only impediment to property registration. Policy experts say that people like Rosas and Nuñez will run into several costly regulatory requirements if they eventually decide to formalize their properties.

The obstacles arose, experts say, due to the government’s decision to eliminate the Registro Predial Urbano, the parallel registry created to speed up formal registration in Lima’s informal settlements.

In 2004, Peru merged the Registro Predial Urbano into Sunarp, the traditional public registry that was seen as too costly and bureaucratic. The Registro’s simpler procedures for second and third property transactions were replaced by Sunarp’s more complicated and costly requirements.

Critics of the decision say the government made the change due to lobbying from powerful groups representing public notaries, who were concerned about losing lucrative business due to the Registro Predial Urbano. Unlike the traditional registry, the Registro allowed property owners to hire any lawyer, not just notaries, to legalize their transactions.

“By returning to the previous system, the costs multiplied by five. People said, ‘No, I’m not going to do that,’” said Ayala, the lawyer and expert on titling. “The issue isn’t cultural. It is about how to maintain the titling process in the formal system.”

Deregularization in Peru has far-reaching consequences for other countries that established their own titling programs based on the Peruvian model.

Argentine economists and Lincoln Institute researchers Sebastian Galiani, of the University of Maryland, and Ernesto Schargrodsky, of the Universidad Torcuato Di Tella, found that in a recently titled suburb of Buenos Aires a significant portion of households were falling back into informality. In a 2013 study, the authors concluded that deregularization was likely due to the unaffordable cost of keeping the properties formal (Galiani and Schargrodsky 2013).

“This isn’t just a Peruvian issue, but something that is much larger in the region,” said Molina, the economist who studied deregularization in Peru. “It is a problem with the short-term view of the reform.”

Potential Solutions

To stem the tide of deregularization, policy experts say authorities will need to intervene now to prevent the need for costly retitling programs in the future.

Some small steps have been taken. In 2007, the government issued legislation to provide lower-income title holders with funds to formalize subdivisions, a process that first requires them to register construction of the house. (Peru’s registration program gave residents titles to the land, but not the house built on top.) However, registration experts say the 2007 program was never fully implemented.

More importantly, experts say the government should reinstate simpler procedures, like those that were discarded when the Registro Predial Urbano was integrated into Sunarp. “The concrete thing to do would be to reconsider mechanisms that were used before,” said Molina. “The Registro was created so that the poor could correctly receive titles.”

Regulatory changes may not be enough on their own. Many experts insist that the problem requires authorities to tackle Peru’s broader culture of informality as well. To do so, they say, the government should launch a campaign to educate residents about the importance of maintaining their properties formal.

“This is a problem that the government has to address,” said Gustavo Riofrio, a sociologist and Lincoln Institute researcher who has spent his career studying property rights. “You have an entire city that was made by these people who are facing the same problem. It is now a social problem, not an individual one.”

Officials at Sunarp say they are working to simplify procedures for property transactions, without jeopardizing the legal security that the current system provides. Sunarp says it is also working to educate people about the importance of using the registry, but acknowledges that the government “hasn’t been able to instill in the population the importance of formalization.”

Until there is a greater acceptance of the regulatory system, some lawyers say Peru should make registration compulsory. Unlike many other countries, Peru does not require registration of property transactions; it’s voluntary.

“We have to educate people so they understand that registration doesn’t just provide security. It’s important to create value as well,” said Ortiz. “But until we have a new culture, we need to require people to register by modifying the civil code.”

At the home of Amalia and Eusebio, in San Juan de Lurigancho, their 40-year-old daughter Emma is eager to discuss property titles.

Emma, who lives in a third-floor apartment with her son, says the subdivision of her childhood home is working out nicely so far. The family members respect each other’s space, but they still get together for a lunch on Sunday. The children also help their aging parents with expenses such as food.

But Emma says she knows it’s important to define ownership legally, especially after seeing cases where other families get mired in legal conflicts over their home. She thinks her parents will eventually start the process to provide their children with titles.

“My mom and dad still feel physically well. When that changes, I think they’ll let it go,” she said. “But for the moment, they are still keeping it tied up. For me, that’s OK.”

Ryan Dubé is a Canadian journalist based in Lima, Peru. His articles have been published in The Wall Street Journal, The Globe & Mail, and Latin Trade. He has also worked on projects for the Economist Intelligence Unit.

References

Fernandes, Edesio. 2011. Regularization of Informal Settlements in Latin America. Cambridge, MA: Lincoln Institute of Land Policy. www.lincolninst.edu/pubs/dl/1906_1225_Regularization%20PFR%20Rev%202012.pdf

Galiani, Sebastian and Ernesto Schargrodsky. 2013. “Land De-Regularization.” Working paper. www.utdt.edu/ver_contenido.php?id_contenido=2674&id_item_menu=4526

Molina, Oswaldo. 2014. “Loss of Plot Formality through Unregistered Transactions: Evidence from a Natural Experiment in Peru.” Working paper. Cambridge, MA: Lincoln Institute of Land Policy. www.lincolninst.edu/pubs/2447_Loss-of-plot-formality-through-unregistered-transactions

Today an estimated one million people are living in subterranean apartments in Beijing, where affordable housing near employment is scarce for the greater city’s 23 million inhabitants (Xing 2011). These units are often windowless subdivisions in basements and air raid shelters, and the median size is 9.75 square meters.

In August 2010, Beijing instituted a three-year plan to evacuate tenants from these underground dwellings. Evictions started taking place in 2011, particularly in the innermost urban districts with expensive land values, but demand remains high. In some areas of the city, particularly in the outer districts, conspicuous signs on the street advertise subterranean rentals, and the Internet lists thousands of units below street level as well.

This article draws on the author’s analysis of this phenomenon from 2012 to 2013, when online advertising for subterranean apartments was active and growing. These listings contain enough information on individual units—including location, price, size, amenities, and depth below ground—to assess the dynamics of this low-income rental housing submarket.

Shortage of Affordable Rental Housing

Like most Chinese cities, Beijing suffers an acute shortage of affordable rental housing, driven by the massive migration to urban centers (Liu et al. 2013; Xie and Zhou 2012). It also has a vast amount of subterranean space, resulting from a policy dating to 1950 that requires all new buildings to have common basements and air defense shelters. Construction codes specify building guidelines, including the provision of infrastructure such as electricity, water, and sewers. This supply of underground space has grown exponentially amid China’s extraordinary building boom in recent decades. Some complexes contain as many as 600 units below street level.

As a means of addressing the housing deficit, official policy for 24 years encouraged the “economic” utilization of this underground space during peacetime, and residential shelter was one of the sanctioned uses (BMBCAD 1986). But in 2010, Beijing stopped granting new use permits for underground apartments and instituted the aforementioned three-year plan to evacuate residents. Given the number of people involved and the lack of affordable housing alternatives, the process has posed challenges, including landlords who demand compensation for occupancy rights they had purchased when the units were legal.

State-Sponsored Housing

Since China transitioned to a private market from a centrally planned economy, wherein the state provided all housing, the real estate sector has grown explosively. Treated primarily as an investment vehicle, new private units are accessible only to those with enough savings to purchase a house with little financing.

Restrictions on land supply are another obstacle to the private provision of shelter. Because the state, which owns all land, is trying to protect fertile farmland, development is prohibited in rural areas on the urban periphery. Nevertheless, informal settlers have rapidly built out that landscape into housing projects. These “urban villages” provide private residences for 5 to 6 million low-income people who cannot afford to live closer to the city center, but the government has been trying to remove them by demolition.

The Chinese state provides four types of affordable housing projects, particularly for public employees with lower incomes (see table 1). The earliest types of assistance included the lian zu fang program, which provided rental housing to the poorest families, and jing ji shi yong fang, which provided subsidized homeownership opportunities.

The government launched a program in 2011 to construct more rental housing (gong zu fang) for recent college graduates and skilled workers in key sectors such as the high-tech industry. Given the relative newness of this program, though, the number of affordable rental units is still relatively small. Meanwhile, xian jia fang housing projects are targeted for the displaced. Despite the large number of units constructed for low-income residents over the years, demand far outstrips supply and wait lists are long.

The Hukou Barrier

Beijing hukou, or household registration permit, is a prerequisite for all four types of affordable housing. A holdover from central planning, hukou entitles households to public services in the place of residence assigned to them by the government, but restricts receipt of services in other locations. People born into hukou of large cities are eligible for better educational, health, and infrastructure services. Unless a state-sponsored employer requests a change of hukou for a worker, those without hukou in major cities still face a significant barrier to economic opportunity.

Figure 1 shows the current location of public housing programs for people with Beijing hukou. As in other places around the world, affordable housing projects are located in more remote parts of the city, as mentioned, where land is less costly but also less desirable. Also typical of affordable housing projects, subletting is reportedly widespread, with program recipients collecting rents for their publicly provided apartments.

Analyzing the Underground Market

Our study took advantage of the detailed listings for underground rentals available at Ganji.com, which were optimal for analysis because the site was well organized, with the greatest number of ads. Using the search term “地下室,” or “underground unit,” we captured the monthly rent, square meter area, specific location, amenities, and other descriptors of subterranean apartments, such as the depth below ground level. Of the 7,312 ads we collected from October 2012 through September 2013, we culled 3,677 unique listings with complete information. As figure 1 shows, these units are well distributed throughout the city, reflecting the requirement that all new buildings in Beijing include underground space.

It is important to mention that the ads represent what is likely the higher end of the underground housing market. Landlords who advertise online tend to be better educated, with more resources. The ads themselves usually feature photos, evincing the relatively high quality of the housing. Moreover, the landlords’ willingness to advertise suggests that they felt relatively secure about their tenure.

Table 2 provides descriptive statistics for the 3,677 subterranean housing units studied. The median size is 9.75 square meters, slightly smaller than Beijing’s 10-square-meter minimum and the overall average housing area per capita (28.8 square meters per person). Even so, the apartments are generally larger than the average worker dormitory housing, which is just 6.2 square meters (Xie and Zhou 2012).

The mean monthly rent of 436 RMB (US$70) confirms that the apartments are at the higher end of migrant housing. A 2012 government study found that about 48 percent of migrants in Beijing pay less than 300 RMB (US$48) per month, 27 percent pay 301 to 500 RMB (US$48–80), and 17 percent pay more than 1,000 RMB (US$160) (Xie and Zhou 2012). In other words, these underground rental units are generally a higher-valued type of shelter for migrants than the more common worker dormitories and urban village housing.

On average, subterranean units are less than 11 kilometers from the city center, with a standard deviation of 6.2 kilometers, placing them well within the 5th Ring Road. With these locational advantages, the apartments offer potentially lower commuting costs and better economic opportunities. Similarly, the average distance to the nearest subway station is a little over 1 kilometer, which is considered within walking distance.

Roughly 50 percent of the advertised units are one or two stories below street level. The other 50 percent are half underground, like so-called “garden apartments” in the United States, with a small window near the ceiling of the room. Our preliminary analysis found that whether a unit was one or two stories below ground did not make any statistical difference in price after holding for other variables. As for amenities, the ads for about one quarter of the units advertised the presence of heating, more than half mentioned Internet connectivity, about one quarter mentioned the presence of surveillance cameras, and less than one eighth mentioned the employment of security guards.

Analyzing Market Dynamics

Our study examined whether demand in this unusual subterranean housing submarket is similar to the conventional market above ground. In particular, the disadvantage of living below street level may be large, and this type of housing is generally so small that other standard variables in hedonic price models may be more pronounced or differ in some other way.

Our statistical analysis involved a step-wise progression of fitting test variables to a base model that includes the variables well established in the literature to be significant. It performed predictably with all the variables significant and in the expected direction. For example, rent increases around 3.3 percent for each square-meter increase in unit size, and 3.6 percent for every one-kilometer decrease in distance to the city center. Transportation access is also significant. Proximity to a subway station raises rent by 1.8 percent per kilometer; for each subway line station within an 800-meter radius of the unit, the rent increases by 2.8 percent.

Given that our hedonic price model performed like other models with the same major significant variables and in the same direction, the underground housing phenomenon is clearly a market. Its emergence suggests that there is strong demand for rental housing—especially among lower-income households—that neither the formal market nor public housing programs are satisfying. This is obvious, given that hukou policies do not allow migrants to apply for public housing programs and that even lower-income Beijingers with hukou have been known to live underground.

Our analysis suggests that the highest priority for the lower-income, often migrant population in Beijing is proximity to jobs and transportation. The central location of these units makes the trade-off of living underground worthwhile. Moreover, the comparison with public housing rents in table 1 indicates that while costs per square meter might be higher, the total rent for underground units is much lower (Hu and Hu 2012). The underground market is thus meeting the demand of people with incomes below the levels targeted by affordable housing programs.

Conclusions

Subterranean living is a sizable phenomenon in Beijing. Thousands of advertisements for underground apartments exist on the Internet, and that number was still growing in 2013 despite evictions. But the size of this submarket does not mean it should be incorporated into public policy.

There have been extraordinary accounts of people living on roofs and in sewer wells, trying to find a way to live in central Beijing. Reliance on underground housing is often just another desperate measure that the urban poor resort to in order to live and work in urban areas where they lack hukou and therefore cannot access services.

How much can a society minimize living space to make urban locations affordable? This question will become even more pressing as densities in Asian megacities exceed levels of acceptable human decency, forcing policymakers and designers to think more creatively about urban reforms. While underground units are in fact more spacious than dormitories for workers or students. China’s extraordinary economic development has raised its citizens’ aspirations and expectations for better housing conditions.

Given the fact that most of the renters are single or couples without children, and tenure is temporary, lasting no more than several years, housing policy should consider the need for lifecycle housing for people just starting out in this expensive city, or for those requiring temporary stays for health care, education, and other needs.

About the Author

Annette M. Kim, Ph.D., is associate professor at the Sol Price School of Public Policy at the University of Southern California. She is also the director of SLAB, the newly formed spatial analysis laboratory at Price that advances the visualization of the social sciences for public service through teaching, research, and public engagement.

References

BMBCAD (Beijing Municipal Bureau of Civil Air Defense). May 15, 1986. “关于改变结合民用建筑修建防空地下室规定的 通知》的实施细则” (Changes to the Implementation Rules on Constructing Air Defense Shelters by Combining with Civil Buildings).

Hu, Hai-feng and Ji-ya Hu. 2012. “Overall Evaluation and Future Development Planning of Beijing Affordable Housing System During the Eleventh Five-Year Plan.” Beijing Social Science 1: 7–14.

Liu, Xiang, Maojun Wang, Jiabin Cai, and Mengchen He. 2013. “An Analysis on the Spatial Structure of Non-Native Permanent Population of Beijing Metropolitan Area in 2000–2010.” Urban Development Studies 20(10): 86–93.

Xie, Xinmei and Le Zhou. 2012. “Study on Housing Demands of Migrant Workers in Key Industries in Beijing.” Paper read at China Urban Planning Annual Conference Proceedings, Beijing.

Xing, Fan. 2011. “北京清理地下空间提速 百万北漂可能无处寄居” (Beijing to Clean Up Underground Space Speed One Million North Drift May Have Nowhere to Sojourn). Beijing Times, January 14. http://news.qq.com/a/20110114/000529.htm

Alrededor del mundo, las ciudades parecen expandirse físicamente y consumir suelo a una tasa mayor que el crecimiento de la población. Cuando la población se duplica, el uso del suelo se triplica.

Cuando se habla del crecimiento de una ciudad en el discurso público, la conversación casi invariablemente se enfoca en la población. Hablamos de ciudades “en ascenso” que crecieron, por ejemplo, de 2 a 5 millones de habitantes en sólo un par de décadas, o ciudades en declinación que se están vaciando y perdiendo residentes a un ritmo rápido.

La unidad común de percepción y medición, en otras palabras, es casi siempre la cantidad de habitantes. Frecuentemente no aparece en la discusión ninguna medición del uso del suelo, a pesar de que las ciudades han crecido mucho más en el uso del suelo que en población entre 1990 y 2015, según los datos del Observatorio Urbano Global de ONU-Hábitat. En los países desarrollados, la población urbana creció un 12 por ciento, mientras que el uso del suelo urbano creció un 80 por ciento. Y en los países en vías de desarrollo, la población urbana creció un 100 por ciento, mientras que el uso del suelo urbano creció un 350 por ciento.

Los problemas del uso del suelo serán cada vez más críticos cuando la población supere los 9.000 millones de habitantes y 2.500 millones de personas migren a las ciudades para 2050, según las proyecciones de las Naciones Unidas. La configuración de las áreas urbanas y los recursos disponibles para recibir esta afluencia masiva serán críticos para sostener la vida humana en el planeta, dice George W. “Mac” McCarthy, presidente y gerente ejecutivo del Instituto Lincoln.

Es un área de profunda preocupación: ¿Cómo están cambiando exactamente los mapas globales estas poblaciones urbanas en crecimiento? Además, ¿podemos observar patrones regulares o incluso predecibles? Y estas tendencias, tal como se ven ahora, ¿se pueden sostener en el tiempo?

A la fecha, hay muy poco conocimiento científico sobre los patrones generales de evolución de los límites, sistemas y el uso del suelo urbano. Pero la nueva segunda edición revisada del Atlas de expansión urbana en línea, publicado por primera vez en 2012, intenta llenar esta brecha crucial de conocimiento. Producido por medio de una asociación entre ONU-Hábitat, el Programa de Expansión Urbana de la Universidad de Nueva York y el Instituto Lincoln, el nuevo Atlas realiza un análisis muy preciso de imágenes de satélite, junto con cifras de población y otros datos, para estudiar la naturaleza cambiante de las ciudades observadas desde 1990 al presente. El informe y los datos completos se difundirán este octubre en la conferencia de ciudades globales del Hábitat III en Quito, Ecuador, como parte de la implementación de la Nueva agenda urbana de la ONU.

El nuevo Atlas analiza 200 ciudades (a diferencia de sólo 120 en la muestra de 2012), seleccionadas rigurosamente de entre las 4.231 ciudades del mundo con más de 100.000 habitantes (al 2010), que constituyen una muestra representativa de las grandes áreas urbanas. Las 200 ciudades en cuestión abarcan el 70 por ciento de la población urbana del mundo.

La división de estadísticas de las Naciones Unidas ha aceptado y adoptado ahora esta “Muestra de ciudades de la ONU” para realizar un análisis continuo de las tendencias de urbanización. “Las ciudades, cómo se forman, y los efectos de la urbanización sobre la calidad de la vida humana deben ser tratados ahora como una ciencia”, dice Joan Clos, Directora Ejecutiva de ONU-Hábitat, durante el lanzamiento en la sede de la ONU en Nueva York en junio de 2016: “La confluencia sin precedentes del cambio climático, el auge de la población y la prisa por vivir en las ciudades quiere decir que nuestro desarrollo humano crítico se producirá en las ciudades”.

Como los asentamientos no planificados redefinen con fluidez muchos límites urbanos, es crucial, dicen los expertos y planificadores, contar con un método sistemático para estudiar las ciudades como unidades espaciales contiguas, no sólo jurisdicciones administrativas. La muestra de ciudades de la ONU también permite pasar de una agenda urbana, con datos a nivel de país, a una agenda predicada en una recolección y el análisis de datos a nivel de ciudad.

El estudio de dicha muestra nos permite inferir ciertas reglas generalizadas sobre las grandes áreas urbanas, señala el coautor de Atlas Shlomo “Solly” Angel, profesor y académico de investigación sénior de la Universidad de Nueva York. “La muestra representa con exactitud ese universo”, dice de las ciudades con poblaciones de 100.000 habitantes o más, “para poder hacer estimaciones sobre dicho universo con información sobre la muestra. Esta es la contribución más científica de este Atlas”.

Consumo del suelo y “de-densificación”

¿Qué podemos decir entonces de las grandes ciudades del mundo, ahora que se han podido obtener y procesar estos datos representativos?

Un patrón evidente observado es que las ciudades alrededor del mundo parecen estirarse físicamente y consumir suelo a una tasa mayor que el crecimiento de la población. Esta tendencia corrobora las conclusiones de la primera edición del Atlas, que pronostica una “densidad decreciente”. En el pasado, esto se denominó “crecimiento desordenado”, y algunos ahora lo llaman “de-densificación”. En cualquier caso, para un planeta cada vez más preocupado con la sostenibilidad, la eficiencia energética, el cambio climático y la escasez de recursos, esta no es una buena tendencia: Una mayor densidad en general crea patrones de vida más verdes y sostenibles.

Angel señala una regla estadística aproximada que emerge del trabajo del Atlas nuevo: a medida que la población se duplica, el uso del suelo se triplica. “Si bien queremos que la densidad aumente o por lo menos permanezca igual, esto no ocurre”, agrega.

Muchos gestores de política no se han dado cuenta, o no han querido darse cuenta, de esta realidad surgida en las décadas recientes. Don Chen, director de desarrollo equitativo de la Fundación Ford, dice que “existe una gran variación en el nivel de conciencia de los funcionarios de planificación sobre el tema de crecimiento sostenible”. En muchos países, agrega, “se observa una gran resistencia de las diversas ortodoxias”, y frecuentemente la predisposición a un cambio en las normas y actitudes oficiales no es favorable: “Por muchas, muchas décadas, y en algunos países por siglos, ha habido incentivos para construir en suelo virgen”.

Y aunque exista la voluntad política de cambiar, hay “mucha capacidad instalada para construir hacia afuera, como por ejemplo en infraestructura de suelo”, señala Chen. Para poder alcanzar una mayor densidad y conservación de suelo, hay que coordinar muchos sistemas complejos más amplios desde una perspectiva política.

De todas maneras, el análisis de datos efectuado en el Atlas –cuyo propósito es ayudar de raíz a definir una nueva “ciencia de las ciudades”– puede servir como una llamada de atención. Angel dice que el Atlas puede ser una “herramienta para convencer a los gestores de política que tienen que prepararse para una expansión considerablemente mayor de lo que sus propios cálculos indican, o de lo que los planificadores han incorporado en sus planes de ordenamiento territorial”.

Para aumentar la densidad habrá que sacrificarse mucho y modificar las normas existentes de vida en muchos lugares: hará falta que la gente viva en apartamentos y casas más pequeñas, en casas multifamiliares y en edificios más altos. También requerirá frecuentemente la remodelación de áreas de baja densidad en las ciudades.

McCarthy reconoce que los datos son “un poco aterradores”, ya que revelan un patrón generalizado de problemas en el futuro. “Este es un proceso que tendremos que parar, llámese ‘crecimiento desordenado’, ‘de-densificación’ o lo que sea”, dice. “No podemos seguir consumiendo todo nuestro mejor suelo con desarrollo urbano. Tenemos que alimentarnos. Tenemos que obtener agua”.

También nota los muchos intentos fallidos de construir grandes complejos de vivienda fuera de las áreas densas urbanas, dejando millones de unidades mayormente vacías alrededor del mundo. Esto ha ocurrido en muchos países, desde México y Brasil a Sudáfrica y China, “¿Por qué seguimos construyendo estos emprendimientos de viviendas en el medio de la nada y esperamos que la gente viva allí?”, dice McCarthy, señalando que es fundamental vincular los trabajos y la actividad industrial con la vivienda.

Claramente, hace falta una planificación más inteligente y proactiva para crecimiento alrededor del mundo, dicen los investigadores del proyecto. Esto quiere decir encontrar las maneras correctas de canalizar el crecimiento de la ciudad dentro del espacio geográfico, y crear la infraestructura (transporte, agua, alcantarillado y otras necesidades) para que los nuevos asentamientos y unidades de vivienda tengan servicios adecuados.

Más aún, también es necesario –según los investigadores del Atlas– que muchas de las grandes ciudades del mundo, desde Lagos, Nigeria hasta la Ciudad de México y Zhengzhou, China, adopten un pensamiento de próxima generación sobre las tan llamadas ciudades “policéntricas”. Eso requerirá superar el paradigma tradicional de ciudades monumentales y monocéntricas con un enorme centro urbano, y crear en vez centros interconectados policéntricos, donde un área metropolitana pueda tener muchos centros entrelazados.

Señales de asentamientos no planificados

Las imágenes de satélite analizadas en el Atlas también identifican otros patrones claves que impulsan y/o simbolizan la tendencia general a la de-densificación en todo el mundo.

Una marca muy granular es la falta de intersecciones de cuatro vías, una clara señal de que los caminos está construyéndose azarosamente, de manera no planificada. Este tipo de informalidad y desarrollo no planificado ha estado aumentando a lo largo del tiempo en todo el mundo. Este patrón, sin embargo, está fuertemente correlacionado con un menor PIB per cápita, y por lo tanto es más pronunciado en el mundo en vías de desarrollo y el Sur global. Asociado a este patrón observado hay un aumento en el tamaño de la manzana urbana, ya que los asentamientos precarios y no planificados de todo tipo crecen sin tener en cuenta las necesidades de transporte.

En efecto, el Atlas también sugiere una falta generalizada de conexiones ordenadas con las vías arteriales, que son clave para facilitar el transporte a los lugares de empleo y las redes económicas. Las áreas edificadas a distancia peatonal de vías arteriales anchas son menos frecuentes de lo que eran en la década de 1990, según los datos de dicha década. Más generalmente, simplemente no hay suficiente cantidad de suelo asignado para caminos.

Además, las áreas de baja densidad y las moradas pequeñas están consumiendo el espacio abierto urbano tan preciado: parques y espacios verdes que pueden hacer las áreas urbanas densas sean más llevaderas.

Angel dice que los planificadores tienen que anticiparse a la ola de migración urbana que se viene y reservar suelo para redes de transporte, viviendas sociales, caminos arteriales y espacios abiertos. Esto se tiene que hacer antes de que se produzcan los asentamientos, ya que cuando eso ocurra los precios del suelo subirán y la logística de desplazamiento de la población se hace más complicada. “Esto se puede hacer ahora a un costo relativamente bajo”, señala Angel. Sugiere que los planificadores comiencen a “hacer algunas preparaciones mínimas”.

Aun en países con un alto grado de planificación central, los datos del Atlas pueden ser útiles para resolver diversos desafíos de gestión del suelo.

“Comparadas con la mayoría de las ciudades del mundo en vías de desarrollo, las ciudades chinas están mejor manejadas”, dice Zhi Liu, director del Programa de China del Instituto Lincoln. “El Atlas sigue siendo útil para China, ya que proporciona datos visuales de expansión urbana y analíticos exactos a los planificadores, para poder comprender mejor la escala y los patrones de expansión urbana en sus ciudades”.

El desafío de los datos del Atlas

Detrás de las nuevas perspectivas analíticas producidas por el Atlas, una importante e intrigante historia de fondo sobre la recolección y el análisis de los datos identifica los desafíos futuros para la teoría urbana y la monitorización de ciudades globales, sobre todo en naciones en vías de desarrollo.

Alejandro “Alex” Blei, un académico de investigación en el programa de expansión urbana del Instituto Marron de Gestión Urbana de la Universidad de Nueva York, señaló que armar las 200 ciudades para la muestra representativa no fue una tarea fácil, ya que no hay una definición aceptada universalmente para un área metropolitana. Los investigadores tuvieron que tomar en cuenta ciertas variables, como su ubicación regional, tasa de crecimiento y tamaño de población, para poder asegurarse que la muestra fuera representativa, y tuvieron que crear una metodología cuidadosa y defendible.

El análisis espacial usó la base de datos del Landsat de NASA, un programa de imágenes satelitales que ha estado recolectando imágenes desde la década de 1970. Si bien este juego de datos científicos y metódicos es de excelente calidad, los datos de población subyacentes, que fueron fundamentales para establecer los patrones de migración y asentamiento, frecuentemente no tenían el mismo nivel de perfección. 

“Algunos países cuentan con programas de datos bien establecidos”, dijo Blei. Pero en otros casos los datos tienen poca resolución y las grandes ciudades, particularmente en el mundo en vías de desarrollo, sólo tienen zonas de censo amplias. Por lo tanto es difícil a veces realizar análisis detallados sobre los cambios de población y su relación con el cambio en el uso del suelo, ya que los investigadores tuvieron que suponer que la densidad se mantiene sobre grandes sectores del área metropolitana en cuestión. 

Al analizar las imágenes de NASA, los investigadores han tenido que estudiar pixel por pixel para diferenciar superficies impermeables del suelo puro. Para ello usaron programas informáticos poderosos en base a métodos bien establecidos, pero su correlación con los datos de población no fue siempre fácil. “Desafortunadamente, no hay mucho que se pueda hacer si los datos no son muy buenos, pero hicimos lo mejor que pudimos bajo las circunstancias”, dice Blei.

Los resultados indican que se necesita un proceso de recolección y síntesis de datos de población menos variable entre países para poder extraer conclusiones más accionables para los gestores de política en cada país individual. Además, hace falta un mayor consenso global sobre la definición de ciudades. La Oficina del Censo de los EE.UU. las define con mucha precisión como “áreas urbanizadas” o “áreas estadísticas metropolitanas”, pero frecuentemente las agencias de recolección de datos de otros países las definen de manera más dispersa. En Asia y África, donde se encuentran las ciudades de crecimiento más rápido, tanto en términos de población como de extensión geográfica, no hay datos de población metropolitana suficientemente granulares como para observar cambios a nivel de barrio. 

Matices globales y futuros inciertos 

La publicación del nuevo Atlas contribuirá, por supuesto, al largo debate producido en círculos políticos y académicos sobre cómo medir el crecimiento desordenado, tanto de alta como baja densidad, y los mejores modelos para abordar estos temas. El nuevo Atlas también contribuye a la amplia literatura de investigación sobre el consumo de recursos y la calidad de vida en contextos urbanos. 

Enrique R. Silva, un asociado de investigación senior del Instituto Lincoln, que se ha especializado en temas de planificación y gobierno en América Latina, señala que la investigación del Atlas seguirá contribuyendo al proceso de planificación y regulación gubernamental, como también a los precios residenciales. El proyecto del Atlas 2016 incluye encuestas con varias partes interesadas en las ciudades, para proporcionar una idea más acabada de las políticas de planificación y los mercados, entre otros temas.

“Sin duda este es un esfuerzo necesario”, dice Silva. “Es un tipo de proyecto de avanzada. Su éxito se medirá viendo cómo otros investigadores, ya sea por medio de críticas o respaldo a la idea inicial, pueden mejorarlo y contribuir a nuestro entendimiento de cómo crecen o se contraen las ciudades”. 

También proporciona una base de conocimientos para aquellos que estudian o generan políticas en ciudades específicas. Silva apunta a un lugar como Buenos Aires, que es un “caso clásico” donde la expansión de territorio ocurre a una tasa más rápida que el crecimiento de la población, y donde muchas personas se desplazan hacia la periferia, alejándose del centro denso de la ciudad. Silva dice que la investigación realizada por su colega del Instituto Lincoln Cynthia Goytia ha demostrado cómo las regulaciones poco estrictas del suelo afectan los patrones de asentamiento. De acuerdo a su investigación, los mercados de suelo y sus regulaciones afectan su capacidad de pago, y esto puede dar lugar a asentamientos no planificados.

Neema Kudva, profesora asociada de la Universidad Cornell y experta en patrones de crecimiento en India y Asia Meridional, también alaba el “trabajado muy cuidadoso” realizado por el equipo del Atlas. Pero sospecha que ciudades más pequeñas, de menos de 100.000 habitantes y por lo tanto excluidas del análisis, puedan tener una dinámica distinta, con patrones y experiencias más variables.

Al tratar de crear “una sola ciencia de las ciudades”, dice, quizás estemos obviando diferencias significativas entre áreas metropolitanas pequeñas y grandes, limitando nuestra capacidad para imaginar intervenciones creativas. “La diferencia entre una ciudad pequeña y otra grande puede estribar en la capacidad para influir en los procesos políticos, la capacidad para obtener fondos, organizar e intervenir”, dice Kudva. “Para una persona como yo, que está realmente interesada en espacios más pequeños, el Atlas proporciona sugerencias, puntos de referencia y contrapuntos importantes, pero éstos no son siempre útiles”.

Kudva también pondera si los cambios emergentes de gran escala relacionados con sistemas energéticos, el calentamiento global, el aumento en el nivel del mar y las convulsiones políticas pueden alterar los patrones globales del uso del suelo con respecto al pasado. El problema de la densidad descendente es potencialmente reversible, según ella. “Esa tendencia podría cambiar”, dice. “Tenemos que jugar un papel más intervencionista”.

De todas maneras, mejores datos e imágenes más detalladas de los patrones de asentamiento pueden ayudar sustancialmente a resolver los desafíos comunes de ciudades de muchos tamaños distintos. Chen, de la Fundación Ford, señala que es necesario realizar investigaciones como las del Atlas para combatir problemas como el acceso desigual a oportunidades. “Necesitamos datos de referencia, y tenemos que comprender la relación entre cómo usamos el suelo y otras cosas”.

El problema de la desigualdad global, que McCarthy llama el “desafío más inexpugnable” de las ciudades, se asoma en todos los datos. Más allá de los múltiples mapas globales del Atlas hay problemas y dilemas perdurables que los investigadores y gestores de políticas sólo están comenzando a comprender y abordar. “El mayor de ellos es la concentración absoluta de pobreza y el aislamiento geográfico de grandes segmentos de la población”, dice McCarthy, notando que a veces del 30 al 50 por ciento de los residentes de muchas ciudades grandes vive en “condiciones deplorables”.

La disponibilidad de viviendas sociales decentes integradas en forma significativa en la red económica y el flujo de las ciudades tiene que ser una prioridad. Pero muchos esfuerzos a nivel nacional han fracasado en este intento. “Este es lo más desconcertante”, dice McCarthy.

Cuando el nuevo Atlas se dé a conocer en la conferencia de ONU-Hábitat III de octubre en Quito, este problema, y muchos otros que afectan las ciudades de mayor crecimiento del mundo, serán analizados en forma más precisa y poderosa gracias a estos datos nuevos y abarcadores. 

John Wihbey es profesor asistente de periodismo y nuevos medios de la Universidad Northeastern. Sus artículos e investigaciones se enfocan en temas de tecnología, cambio climático y sostenibilidad.

Crédito: Programa de Expansión Urbana de la Universidad de Nueva York

Cities around the world seem to be stretching out physically and consuming land at a rate that exceeds population growth. As populations double, land use triples.

When city growth comes up in public discourse, the conversation almost invariably focuses on population. We speak of “booming” cities that have grown from, say, 2 to 5 million in just a few decades or declining cities that are hollowing out and losing residents at a rapid rate.

The common unit of understanding and measurement, in other words, is almost always the number of people. Measures of land use are often missing from the picture, despite the fact that cities grew much more in land use than in population between 1990 and 2015, according to data from the UN-Habitat Global Urban Observatory. In developed countries, urban population grew 12 percent, while urban land use increased by 80 percent. And in developing countries, population expanded by 100 percent while urban land use rose 350 percent.

Land use issues will become more critical as the world population exceeds 9 billion and 2.5 billion persons migrate to cities by 2050, according to the United Nations’ projections. Configuring urban areas and their available resources to support this massive inflow will be critical to sustaining human life on the planet, says George W. “Mac” McCarthy, president and CEO of the Lincoln Institute.

It’s a profound area of concern: How exactly are these rising urban populations changing global maps? Further, can we observe regular, even predictable, patterns? And are these trend lines, such as they are, sustainable over time?

To date, there has been little scientific understanding of broad global patterns related to how city borders, systems, and land-use patterns are changing. But the newly revised, second edition of the online Atlas of Urban Expansion, first published in 2012, aims to fill this crucial gap in knowledge. Produced through a partnership among UN-Habitat, the New York University Urban Expansion Program, and the Lincoln Institute, the new Atlas performs very precise analysis of satellite imagery, coupled with population figures and other data, to study the changing nature of cities observed from 1990 to the present. The full report and data are set to be unveiled this October at the Habitat III global cities summit in Quito, Ecuador, as part of the implementation of the UN’s New Urban Agenda.

The new Atlas analyzes 200 cities (up from 120 in the 2012 sample), rigorously selected from among the 4,231 cities in the world with populations greater than 100,000 (as of 2010) that constitute a representative sample of large urban areas. The 200 cities in question make up about 70 percent of the world’s urban population.

The United Nations statistics division has now accepted and adopted this “UN Sample of Cities” as a way to conduct ongoing analysis of urbanization trends. “Cities, how they form, and the effects of urbanization on the quality of human life must now be treated as a science,” says Joan Clos, executive director of UN-Habitat, during the launch at UN headquarters in New York in June 2016: “The unprecedented confluence of climate change, population boom, and the rush to live in cities means that our critical human development will take place in cities.”

With unplanned settlement fluidly redefining many urban boundaries, it is crucial, experts and planners say, to produce a consistent method for studying cities as contiguous spatial units, not just administrative jurisdictions. The UN Sample of Cities also enables transition from an urban agenda based on country-level data to one predicated on city-based data collection and analysis.

Studying such a sample allows us to infer some generalizable rules about large urban areas, notes Atlas coauthor Shlomo “Solly” Angel, a professor and senior research scholar at New York University. “The sample accurately represents that universe,” he says of cities with populations of 100,000 persons or more, “so you can actually make statements about that universe given information about the sample. That’s the more scientific contribution of this Atlas.”

Land Consumption and “De-densification”

What, then, can be said of the world’s large cities, now that such representative data have finally been collected and crunched?

One reliably observed pattern is that cities around the world seem to be stretching out physically and consuming land at a rate that exceeds population growth. This tendency corroborates the findings of the first-edition Atlas, which indicates “falling density.” In the past, this was termed “sprawl,” and some refer to it now as “de-densification.” In any case, for a planet increasingly concerned with sustainability, energy efficiency, climate change, and resource scarcity, this is not a good trend: Density generally allows for greener and more sustainable living patterns.

Angel notes that there is a kind of rough statistical rule that emerges from the new Atlas work: As populations double, land use triples. “Even though people would like to see densification increase or at least stay the same, it doesn’t,” he adds.

Many policy makers have been unable, or unwilling, to see this reality unfolding in recent decades. Don Chen, director of Equitable Development at The Ford Foundation, says that the issue of sustainable growth is “very uneven in terms of planning officials’ awareness.” In many countries, he adds, “various orthodoxies are battling it out,” and frequently the “cards are stacked against us” in terms of changing norms and official attitudes: “For many, many decades, and in some countries for centuries, there have been incentives [for] building on virgin land.”

And even where there is political will for change, there are “multiple dimensions of capability to build upward, such as in-ground infrastructure,” Chen notes. Wider complex systems must be coordinated from a policy perspective in order to achieve greater density and land conservation.

In any case, the data analysis effort undertaken in the Atlas—which at root is intended to help define a new “science of cities”—may serve as a wake-up call. Angel says the Atlas can be a “tool for convincing policy makers that the expansion they must prepare for is considerably larger than their own little back-of-the-envelope calculations, or what their planners have in their master plans.”

Increasing density again will necessitate sacrifice and modification of existing norms for living standards in many places: It will require people to live in smaller apartments and homes, in multifamily housing, and in higher buildings. It also will frequently require redevelopment of low-density areas in cities.

McCarthy acknowledges that the data are “a little bit chilling,” as they reveal a pervasive pattern that signals huge trouble ahead. “It’s something that we have to stop—whether we call it ‘sprawl’ or ‘de-densification’ or something else,” he says. “We can’t continue to consume all of our best land with urban development. We still have to feed ourselves. We still need to collect water.”

He also notes many ill-fated attempts to build large housing units far outside denser urban areas, leaving millions of units across the world largely empty. This has happened in many countries, from Mexico and Brazil to South Africa and China. “Why is it that we continue to build these developments in the middle of nowhere and expect people to live there?” McCarthy says, noting that it is vital to link jobs and industrial activity with housing.

Clearly, smarter, more proactive planning is required for growth across the world, the project’s researchers say. That means finding the right ways to channel city growth spatially and to create the infrastructure—transportation, water, sewer, and other necessities—so the new settlements and housing units are serviced appropriately.

Moreover, it is also necessary, Atlas researchers say, for many of the big cities around the world—from Lagos, Nigeria, to Mexico City to Zhengzhou, China—to adopt more next-generation thinking about so-called “polycentric” cities. That will require moving beyond the traditional paradigm of hulking, monocentric cities with a huge urban core and instead creating polycentric networked hubs, whereby a metropolitan area will have many interlinked urban centers.

Signatures of Unplanned Settlement

The satellite imagery analyzed in the Atlas also highlights other key patterns that are both drivers and/or symbols of the overall de-densification trend worldwide.

One very granular mark is the lack of four-way intersections, a clear sign that roads are being laid out haphazardly, in a largely unplanned way. Such informality and unplanned development have been increasing over time across the world. The pattern, however, is strongly correlated with lower GDP per capita, and therefore is more pronounced in the developing world and global South. Linked to this observed pattern is an increase in urban block size, as shantytowns and unplanned settlements of many kinds grow without regard to transportation needs.

Indeed, the Atlas also suggests a pervasive lack of orderly connections to arterial roads, which are key to facilitating transportation to employment and economic networks. Built-up areas within walking distance of wide arterial roads are less frequent than they were in the 1990s, according to data from that decade. And more generally, there is simply not enough land being allocated for roads.

In addition, low-density tracts and small dwellings are unnecessarily consuming precious urban open space—parks and green spaces that can make dense urban areas more livable.

Angel says planners need to get ahead of the coming wave of urban migration and secure land for transportation, affordable housing, arterial roads, and open space. That needs to be done before settlement happens, when land prices subsequently soar and the logistics of moving populations become trickier. “This can be done at a relatively small cost,” Angel notes. He suggests that planners begin to “make some minimal preparations for it.”

Even in countries where there is a high degree of central planning, the data contained in the Atlas may prove helpful for diverse land management challenges.

“Compared to most cities in the developing world, Chinese cities are better managed,” says Zhi Liu, director of the Lincoln Institute’s China program. “The Atlas is still useful for China, as it provides accurate, visual urban expansion data and analytics to planners that could strengthen their understanding of the scale and patterns of urban expansion in their cities.”

The Atlas Data Challenge

Behind the new analytical insights produced by the Atlas, an intriguing and important backstory of data collection and analysis highlights future challenges for urban theory and monitoring of global cities, especially in developing nations.

Alejandro “Alex” Blei, a research scholar in the urban expansion program of New York University’s Marron Institute for Urban Management, said that assembling the 200 cities for the representative sample was no easy task, as there is no universally accepted definition for a metropolitan area. Researchers had to account for variables such as regional location, growth rate, and population size in order to ensure the sample was representative, and they had to create a careful and defensible methodology.

NASA’s Landsat database, a satellite imagery program running since the 1970s, was the basis for the spatial analysis. While that methodical, scientific dataset is of exceedingly high quality, the underlying population data, which was key for establishing migration- and settlement-related patterns, was frequently less than perfect.

“Some countries have very well-established data programs,” Blei said. But in other cases the data are very “coarse,” and large cities, particularly in the developing world, have only broad census zones. It is therefore difficult, at times, to make fine-grained insights about population changes in connection with land use shifts, as the researchers had to assume equal density over large tracts of the metropolitan area in question.

Scanning the NASA pictures, the researchers had to analyze pixels to assess whether there was impervious coverage surface or soils. They performed this task with powerful software according to well-established methods, but correlating it with population data was not always smooth. “Unfortunately, there’s not very much we can do if the data are not very good, but we did the best we could under the circumstances,” Blei says.

Evidence suggests the need for less variation in population data collection and synthesis across countries, in order to derive more actionable insights for policy makers in every country. And more global consensus is needed around the definition of cities. The U.S. Census Bureau defines them very precisely as “urbanized areas,” or “metropolitan statistical areas,” but they are frequently defined in more scattered ways by other countries’ data collection agencies. Asia and Africa—home of many of the fastest-growing cities, both in terms of population and geographic extent—suffer from a lack of granular city population data that speak to neighborhood-level change.

Global Nuances and Uncertain Futures

The publication of the new Atlas will, of course, join a long debate in policy and academic circles about how to measure sprawl, both high- and low-density, and the best models for addressing related issues. The new Atlas also speaks to a long research literature on the consumption of resources and quality of life in urban contexts.

Enrique R. Silva, a senior research associate at the Lincoln Institute who has specialized in Latin American planning and governance issues, notes that the Atlas research will continue to help advance understanding of government planning and rule-making, as well as residential pricing. The 2016 Atlas project includes surveys conducted with various stakeholders in cities that might yield insights on planning policies and markets, among other issues.

“It’s definitely an effort that is needed,” Silva says. “It’s a first-mover type of project. The measure of success will be the extent to which other researchers, whether through critique or support of the initial idea, can improve upon it and contribute to our understanding of how cities are growing, or even contracting.”

It will also help ground-level understanding for those studying or making policy in particular cities. Silva points to a place like Buenos Aires, which he calls a “classic case” where the expansion of territory is occurring faster than the population growth—and where many people are being displaced outward from the denser city core. Silva says that research by his Lincoln Institute colleague Cynthia Goytia has shown how lax land use regulation affects settlement patterns. Land markets and their regulations affect affordability, and this can result in unplanned settlements, her research suggests.

Neema Kudva, an associate professor at Cornell University who is an expert in growth patterns in India and South Asia, also praises the “very careful work” performed in the Atlas effort. But she worries that smaller cities—those under 100,000 and therefore excluded from the analysis—may see different dynamics that are subject to more variable patterns and experiences.

In trying to create “one science of cities,” she says, we may miss significant differences between small and big metropolitan areas, limiting our ability to imagine creative interventions. “The difference between small and big can be the ability to influence political processes, the ability to garner funds, to organize, to intervene,” Kudva says. “For a person like me who is interested in smaller places, things like the Atlas provide important suggestions, important points of reference, important counterpoints, but they are not always useful.”

Kudva also wonders if large-scale, emerging changes related to energy systems, global warming, sea-level rise, and political upheaval may alter worldwide land use patterns, compared to those observed in the past. The issue of falling density is potentially reversible, she believes. “That trend could change,” she says. “We need to play a more interventionist role.”

Still, better data and a more detailed picture of settlement patterns can substantially help address challenges common to cities of many different sizes. Chen, of the Ford Foundation, notes that research like the Atlas is necessary to combat issues such as unequal access to opportunity. “We need baseline data, and we need to understand the relationship between how we use land and other things.”

The issue of global inequality, which McCarthy calls the biggest “unassailable challenge” of cities, looms in all of the data. Beyond the layers of the Atlas’s global maps are stubborn facts and dilemmas that researchers and policy makers are only beginning to understand and address. “The biggest one is the absolute concentration of poverty and geographic isolation of large segments of the population,” McCarthy says, noting that sometimes 30 to 50 percent of residents in many large cities live in “deplorable conditions.”

Decent affordable housing that is meaningfully integrated into the economic network and flow of cities has to be a priority. Yet many national efforts to date have failed to achieve that goal. “That’s the thing that I find most vexing,” McCarthy says.

As the new Atlas is rolled out in October at the UN-Habitat III conference in Quito, that issue—and many others affecting the world’s fast-growing cities—is sure to be framed even more precisely and powerfully by the new, comprehensive data.

John Wihbey is an assistant professor of journalism and new media at Northeastern University. His writing and research focus on issues of technology, climate change, and sustainability.

Image by New York University Urban Expansion Program

Land readjustment is a vital but difficult and time-consuming process: formulating a sort of retroactive version of planning in neighborhoods that developed informally, with unsanctioned dwellings chaotically built in ways that leave some with no access to streets and paths. According to UN-Habitat, 863 million people around the world lived in such settings as of 2014, and the number could rise to 3 billion by 2050. The agreed draft of the New Urban Agenda for the Habitat III conference in Quito, Ecuador, notes that the “rising number of slum and informal settlement dwellers” contributes to intense challenges that exacerbate global poverty and its risks, from a lack of municipal services to increased health threats.

But evolving technology may facilitate revision of these organic layouts in ways that lead to minimal displacement and speed the absorption of such neighborhoods into a city’s formal structure, thus providing residents basic services—from sanitation and drainage systems to access for fire and medical emergencies. One of the more promising tools is Open Reblock, a platform currently in a pilot phase in areas around Cape Town, South Africa, and Mumbai, India. The project stems from a collaboration among Shack/Slum Dwellers International (SDI, is a network of urban-poor communities in 33 countries), the Santa Fe Institute (SFI, a nonprofit research and education organization), and Arizona State University. 

SDI has long been involved in grassroots “reblocking”—essentially another way of characterizing the land-readjustment process. Luís Bettencourt, a professor of complex systems at the Santa Fe Institute, explains that his group, which focuses on “cities as systems,” began working with SDI a few years ago. There was a useful convergence in the high-level, statistics-and-data thinking of the SFI group with the on-the-ground “census” efforts SDI used in its work with informal-settlement communities. 

SDI’s reblocking efforts could be painstaking. Residents led the process of mapping a neighborhood—on paper. Then they gathered at community meetings, arranged cutouts representing every local structure over that map, and began shifting them around to devise new paths and roadways. While this active collaboration was profoundly beneficial, the analog methodology wasn’t exactly speedy. 

Ever-more-accessible digital technology has in recent years eased the process, says SDI Programme Officer: Data Management Anni Beukes. The group now uses a geographic information system (GIS) tool to map settlement boundaries and services available, and then relies on a separate tool for detailed household-level surveys and precise measurements of every structure. Given the wide availability of mobile devices, the process is open to—and indeed dependent on—direct resident participation. 

Enrique R. Silva, research fellow and senior research associate at the Lincoln Institute, notes that similar tech-mapping tools are impacting such efforts around the world. “You can map something almost immediately,” he says, and involve community members in that process. He points to efforts, backed by the Lincoln Institute and others, that rely on “cheap and universal” devices and crowd-sourcing tools to reach similar goals across Latin America.

A master map that is available in digital form also creates new possibilities. Open Reblock is an example. It deploys a custom algorithm to read a digital map of an informal settlement and propose what it sees as the optimal strategy for reblocking it. (The algorithm is written to prioritize existing roadways and structures, echoing the traditional goal of minimizing displacement.) This process takes just minutes, at most. 

“When I first showed it to our communities, they said, ‘You’re taking our paper cutouts away’!” Beukes says with a laugh. They weren’t wrong—and they weren’t actually protesting. (“At least the younger ones weren’t; some older participants,” she adds, “can be hesitant in their uptake of new technology.”)

But what Open Reblock produces is not meant to be a strict directive or an end point—community members can still tweak the results based on their direct knowledge and concerns. Indeed, Open Reblock depends on such participation—“creating a shared reality where people can play and create this future reality,” Bettencourt says. “It’s basically a town-planning tool, at the level of a neighborhood.” And by offering “a proof of principle and a starting point” for negotiations, he adds, it radically speeds up one of the toughest steps in the process. 

Beukes says participants in the pilot programs have reacted with enthusiasm toward the new possibilities of this system. It means that a final plan will exist in a form that city officials can respond to more easily, and it ensures that all parties are considering the same geospatial data and planning scheme. “It’s a template for discussion,” Bettencourt adds, one that “puts everyone literally on the same map.” 

With a grant from Open Ideo, Bettencourt’s team and SDI are working to improve the design of Open Reblock’s interface, with feedback from community participants in Cape Town and Mumbai. The entire project is being created in open-source code (available on Github), both to encourage improvements from anyone who wants to be involved and to make it easier to scale up future versions for widespread use anywhere. 

The project is, of course, not a magic solution. Land readjustment can be contentious, and Silva points out that important issues around the value of any given settlement dweller’s property must still be worked out on a more individual, human level. Bettencourt and Beukes agree that Open Reblock is a supplement to, not a substitute for, existing processes.

Still, Bettencourt points to UN-Habitat numbers to speculate that there may be a million neighborhoods around the world in need of reblocking. “That’s a scary number,” he says. And it adds to the sense among some observers that there’s just something impossible about the effort—particularly when, on a case-by-case basis, the process gets bogged down over time. 

But all this may be less intimidating from a technologist perspective. Think of the mapping and data-collection tools that have emerged in recent years as an early step that builds on the long-existing work of SDI and others. Open Reblock is just one more iteration of that trajectory. “I think we have all the ingredients, but we have to start doing,” Bettencourt says. “If there’s a system to capture the data and run proposals on top of it, that’s a big step. It doesn’t create the change, but it helps.”

Rob Walker (robwalker.net) is a contributor to Design Observer and The New York Times.

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