For much of the 20th century, moving to a big city was seen as a path to greater prosperity and opportunity. However, a new study combining satellite data with city records suggests that major metropolitan areas have ceased functioning as effective springboards for social and financial mobility since the mid-20th century.
Dylan Shane Connor from Stanford University’s Center for Advanced Study in the Behavioral Sciences and his team analyzed how urban areas’ size, density, and connectivity in an individual’s birth county influenced their social and economic mobility over time.
“The United States, and big cities in particular, have been in a long trend of declining community engagement and social capital and rising levels of family instability,” Shane said in an email to The Debrief. “For a variety of reasons, these factors are powerful predictors of children’s chances of achieving upward mobility. Sprawling metropolitan areas and population-dense cities fare poorly in these respects.”
“We also like to think of American cities as exemplifying diversity. Yet, the evidence increasingly suggests that there is actually less social interaction across [the economy] and class in cities than in other contexts,” he says. “This is critical because children from poorer backgrounds can also benefit a lot from interacting with children from advantaged backgrounds.”
Satellite data and City Records Reveal What Happens as Cities Grow
The study found that as cities grew, social mobility—the ability of people to improve their socioeconomic status across generations—declined. Between 1920 and 1950, urban expansion was associated with greater social mobility. However, from 1950 to 1990, the trend reversed, with densely populated areas seeing a drop in upward mobility.
A similar pattern emerged with inequality. In the early 20th century, urban growth helped reduce economic disparities, but in later decades, it exacerbated them. Today, as cities expand, residents tend to have weaker social connections, with lower participation in community groups, fewer friendships, and diminished civic engagement. Connor and his team suggest that these eroding social ties may be a key reason why large cities no longer provide the same opportunities they once did.
Beyond social fragmentation, policy decisions have also contributed to declining intergenerational mobility. Without strong political and social support systems, many families struggle to navigate an economic structure that does not promote equality.
“In general, there is not enough support for families,” Connor explained. “The gap between single-parent households and two-parent households in the United States is significantly larger than they are in many European countries. This is partly because families are better supported in Europe, which helps narrow the gap. The lack of affordable housing is also a critical challenge, and there is a lot of serious thinking about how to address those problems.”
One major factor contributing to rising inequality in urban areas is the distribution of public goods—such as education, transportation, and social services.
“The radically decentralized manner by which many key public goods are provided in the US is another key factor,” Connor explains. “This differs strongly from most other analogous high-income countries (Canada, the UK, etc.), and this has a major independent effect driving segregation, but also poor outcomes in what end up being sharply income-segregated communities.”
“In larger cities, which have become highly income and wealth unequal compared to many smaller communities, there has become much more scope for this kind of segregation—so, as we say in our paper, urban size, economic change, and segregation end up reinforcing each other, to the detriment of the poor.”
Rethinking Urban Development
Knowing this, policy and urban development changes could address these fundamental issues head-on. Connor argues that urban density and expansion have weakened social capital, but this outcome is not inevitable. He suggests that reshaping urban growth could improve social mobility.
To achieve this, he proposes a two-part policy approach: decentralizing large cities into interconnected smaller communities to reduce segregation while simultaneously centralizing resources to ensure disadvantaged urban areas receive adequate public funding.
“This is a radical policy project, but let’s be clear, the challenges to overcoming the issues we raise in this paper require big rethinking,” Connor told The Debrief, acknowledging that this proposed outcome is a fundamental shift in how cities are currently designed.
Connor added that some of the developments he outlines are already happening, “partly as a result of longer-term trends to suburbanization but also strengthened by post-COVID WFH.
“But that trend is far from enough on its own,” he says. “It needs to be met with major changes in urban design, fiscal federalism, public transit, zoning, housing affordability, etc., to enable great social cohesion and improve family circumstances.”
While cities have historically been economic and social progress engines, Connor’s study suggests that their role has shifted over time. The decline in social mobility and rising inequality in urban areas indicate a need for policy interventions that promote stronger social networks, equitable distribution of public goods, and a reimagining of urban design to better serve future generations.
Chrissy Newton is a PR professional and founder of VOCAB Communications. She hosts the Rebelliously Curious podcast, which can be found on The Debrief’s YouTube Channel. Follow her on X: @ChrissyNewton and at chrissynewton.com.