The Nemeses of Cities

The Plague of Athens ended the golden age of the West’s first great city in 430 BC—not only because of the disease but also because, as Thucydides wrote, “Athens owed to this plague the beginnings of a great state of unprecedented lawlessness.” Justinian’s attempt to revive the Roman Empire collapsed when a pandemic struck Constantinople in AD 541. Europe then sank into centuries of warfare and rural poverty. Contagious diseases, like cholera, routinely depopulated cities throughout the nineteenth century, until local governments made enormous investments in water systems and improved public hygiene. “Times of pestilence,” wrote the great classical historian Barthold Georg Niebuhr in 1816, “are always those in which the animal and devilish in human nature assume prominence.” While that claim is far from universally true, past pandemics have sparked riots, pogroms, and unrest.

And even before Covid-19, discontent seethed in America’s cities—and reemerged dramatically in both the heartfelt protest and the deplorable looting and violence that followed the death of George Floyd in Minneapolis on May 25, 2020. Protests have broken out against gentrification, Uber, new housing projects—and the absence of new housing projects. Police have been vilified. Unhappiness about the glaring inequities in schooling, income, and upward mobility is widespread. The city triumphant has become the city discordant.

This discontent reflects both a heightened sense of possibility and a correspondingly potent capacity for despair. When New York suffered more than 2,245 murders in 1990, reducing crime seemed the top priority. Now that New York has fewer than 400 murders annually, citizens want more than just tough policing. When the city teetered on bankruptcy, no one expected New York to right every social injustice. As the city’s wealth expanded, so have people’s hopes. When those hopes get smashed, as they were when millions watched the searing video of police officer Derek Chauvin crushing the life out of George Floyd, discontent erupts, and the righteous anger of the many provides cover for the lawless urban destruction of the few.

America’s cities are places of great productivity for adults, true—but not of upward mobility for the young. Successful cities are increasingly unaffordable largely because they build too little new housing. City governments have failed to tame traffic, or to address the discontent over law enforcement in many poorer communities. Most pressingly, urban governments did not prepare adequately to face a new pandemic.

The urban public sector has almost always lagged behind the urban private sector. In the mid-nineteenth century, the infrastructure and institutions needed to make New York sanitary and humane remained decades away. A great movement of reformers—including Teddy Roosevelt and Stephen Smith—fought to make cities safer from crime and disease. Others, such as Peter Cooper, dedicated themselves (or their fortunes) to improving urban education and opportunity. If twenty-first-century cities are to overcome their failures, they will need comparably capable, pragmatic leaders who dedicate themselves to preventing pandemics, promoting opportunity, and ensuring that policing is both effective and humane.

Behind the current anger lurks a widespread sense that the benefits of cities are accruing only to a privileged few. Cities should never apologize for inequality: they have poor and rich people because they have been relatively good places to be rich and less difficult places to be poor. Urban density attracts the poor with better public transportation, accessible social services, and plentiful service-sector jobs. Inequality is another name for economic diversity.

But cities should take pride in that diversity only if they fulfill their historical mission of transforming poor people into wealthier people. Impoverished farmers found a better future in the London of 1750 or the Chicago of 1950. Economists Sam Asher and Paul Novosad document how intergenerational mobility is much higher today in urban India than in that country’s rural areas. Yet the children of urban America today appear to be less upwardly mobile than their nonurban counterparts.

Data assembled by economist Raj Chetty and his coauthors in the Opportunity Atlas project link the adult earnings of people born between 1978 and 1983 with their parents’ earnings. The data convert income into percentiles; if a parent’s income is greater than that of 30 percent of all households, that parent’s income is labeled “30th percentile.” This same procedure is followed with the second generation’s adult income, comparing it with that of contemporaneous households. The core measure of upward mobility—available at the neighborhood, city, and county level—is the average income percentile that children born to parents in the 25th percentile earn as adults.

In lower-density areas, it turns out, the children of 25th-percentile parents ended up at the 44th percentile of the U.S. income distribution as adults. In the most densely populated metropolitan areas, the children wound up earning less than the 40th income percentile. The low-density children, that is, leaped 19 income percentiles above their parents; high-density kids saw their income levels increase by less than 15 percentiles.

This fact is surprising because cities are so good for productivity and skill acquisition among adults. In the densest parts of America, per-capita gross domestic product is typically more than double per-capita GDP in the least dense metropolitan areas. New York’s per-capita GDP is $92,000—double the level found in almost one-third of America’s metropolitan areas. Adult wage growth is faster for people who come to cities, suggesting that these are places where workers learn to become productive.

Still, urban children seem to end up poorer. One possible explanation is that urban parents 40 years ago earned more than their skills would warrant, precisely because cities were so productive. On that view, a parent at the 25th income percentile in Des Moines, Iowa, in 1979 was far more skilled than a parent earning the same amount in New York City. Perhaps the Iowa parents’ greater skills translated into greater earnings for their children. That hypothesis cannot explain, though, why density also appears to reduce upward mobility within cities—and it does. Children growing up in the densest urban neighborhoods earn five income percentiles less than their peers raised in moderate-density neighborhoods. Children who grew up in the absolute center of the city earn, on average, six income percentiles less than kids from eight or more miles from the city center. Parents living in different neighborhoods within a metropolitan area are still part of the same labor market, and if they have the same incomes, they should have roughly the same level of skills—so what is going wrong with their children?

Cities may fail children by offering too many distractions from education—from entertainment to potentially less wholesome pursuits. And they certainly make it easier for parents to find something more fun to do than nagging kids about homework. Older, industrial cities may also contain environmental hazards, such as lead, that harm cognitive development. Perhaps most plausibly, cities enable more segregation by income and by race, and it is this that may be harming poor children the most. An adult who lives and sleeps in a segregated neighborhood typically works in an integrated, and often vibrant, urban business district. The world of that person’s child, though, is more likely to be limited to a segregated apartment building and school. Cities can connect adults and still leave children isolated.

These hypotheses suggest that reductions in children’s skill acquisition may be a downside of density. The vast number of urban neighborhoods enable sorting by neighborhood. Adults naturally sort into communities with similar people. That sorting can end up harming children, by leaving them in an isolated island of poverty, even within a rich city.

And plenty of evidence exists that urban schools failed the generation covered by the Opportunity Atlas research. The data show a break in upward mobility just at the border of any big-city school district. On average, the adult earnings of children who grew up just outside the big-city school district are three percentiles higher than those of children growing up inside that district. The probability of being in prison or jail as an adult also drops significantly at the district border.

Twenty years ago, I hoped that education reformers would radically improve city schools. The Opportunity Atlas data are a generation out of date, and it’s possible that school reforms over the past 20 years have made cities better for kids. Nevertheless, test-score improvements have been slow, and the political forces arrayed against change have been strong.

A second urban failure concerns space. In the Boyle Heights neighborhood of Los Angeles, anti-gentrification activists don’t just organize the occasional weekend march. For the black-jumpsuit- and red-ski-mask-wearing activists of the Boyle Heights Alliance Against Artwashing and Displacement (or B.H.A.A.A.D.), picketing the offending art galleries and fancy coffee shops is standard. One gallery wound up vandalized with spray paint. Another had its website hacked, with visitors finding a fake apology for “hipster bro gentrifiers who have colonized Boyle Heights with our gallery.” Two art-gallery owners even reported death threats.

This conflict over gentrification is so fierce because Los Angeles’s supply of affordable space is so sparse. The National Association of Realtors reports that the median sale price of an L.A. condominium was more than $470,000—higher than in any other metropolitan area except San Francisco. For a home in the L.A. metropolitan area, the median price was $611,000 in 2019—almost 60 percent more than in greater New York. High costs tend to push galleries, coffee shops, and better-educated residents into formerly working-class enclaves like Boyle Heights, angering many long-term residents.

The space shortage reflects a combination of robust demand and constrained supply. Los Angeles is an economic engine, like New York or Chicago, but one with palm trees and better beaches. The American attraction to a Mediterranean-like climate is undeniable and has helped drive L.A.’s growth. As late as 1970, however, that climate didn’t translate into particularly high home prices, because Los Angeles built plenty of new housing. From 1940 to 1970, the number of housing units in Los Angeles County rose by 164 percent, or 1.58 million units. Construction has contracted dramatically since. From 1990 to 2015, L.A. County added only 340,000 housing units, an 11 percent rise.

This isn’t about lack of land. The county encompasses more than 3 million acres, but its current density level reflects only 1.15 housing units per acre. That’s a strikingly low number for America’s most populous county.

Los Angeles’s transformation from builders’ paradise to anti-construction bulwark mirrors the national trend of empowering insiders at outsiders’ expense. While nineteenth-century cities may have failed to moderate density’s downsides, they did not block new buildings and businesses. Political machines, like New York’s Tammany Hall, knew that growth was good for the city and for the machine’s bottom line.

But over the past 50 years, while politics has become more transparent and inclusive, the antidevelopment fears of homeowners have often trumped the pro-building desires of businesses and developers. As the growth in supply shrank, prices in high-demand areas like L.A. rose. Rising prices create conflict over scarce space. The battle over Boyle Heights would end if it were easier to add density in other parts of the city.

Restrictions on building in America’s most productive metropolitan areas have other adverse consequences. Too many people, for instance, are relocating from productive cities to less productive places with abundant, cheap housing. Before 1980, less educated Americans migrated to states with higher wages, but Peter Ganong and Daniel Shoag show that this “directed” migration has declined, probably because high-wage places aren’t building enough. New construction also dampens housing-price fluctuations, since housing bubbles are another side effect of curbing construction.

An even more basic function of city government is to counter the natural disadvantages—from traffic jams to crime to contagious disease—of living so close to millions of other human beings. Before 2020, the primary downside of density that seemed to be worsening was street congestion. Crime and policing, though, were also becoming topics of discontent in many urban areas. Now, the Covid-19 pandemic reminds us that contagious disease will always be the greatest threat to high-density living.

The Texas Transportation Institute’s 2019 Urban Mobility Report found that the costs of urban congestion rose from $15 billion in 1982 to $179 billion in 2017, corrected for inflation. The average commuter wasted 20 hours per year in traffic in 1982 and 54 hours annually in 2017. Just as the housing-affordability problem reflects the collision of robust demand with a fixed supply of structures, long commutes reflect too little road space to accommodate the strong demand for urban mobility.

In the nineteenth century, technological marvels enabled faster mobility within cities. Horse-drawn omnibuses, followed by streetcars and trolleys, and then by elevated railroads and subways, sped transportation rapidly, letting cities spread out. The automobile was the most revolutionary mobility technology yet, and it reshaped urban America in the twentieth century by enabling mass suburbanization and the move to car-oriented Sunbelt cities.

Unfortunately, the autonomous nature of car travel makes congestion even more severe. Subway and streetcar companies control the number of vehicles on their systems. Congestion on rail carriages is constrained by the prices that these private companies impose. But automobile congestion encounters no natural limits. Building new roads does little to ease congestion in crowded urban areas; as the work of Gilles Duranton and Matthew Turner documents, new drivers quickly appear, clogging those roads, too.

Charging drivers to use city streets is the natural congestion fix. The basic principle that people should pay for the social costs of their actions is so central to public economics that economists often seem perplexed by the broad opposition to congestion pricing. It remains to be seen whether New York City will implement congestion pricing in 2021, as planned. A political system to ruffle insiders’ feathers will find imposing costs on drivers to be as difficult as permitting new construction.

The George Floyd protests represent the limits of what was long regarded as the public sector’s greatest modern urban success. Until the last five years, crime-fighting seemed like a triumph, not only in New York but also in other cities. Chicago’s murder rate declined from more than 30 homicides per 100,000 inhabitants in the early 1990s to about 15 homicides per 100,000 in the early 2000s, and Los Angeles became much safer, as well. Since then, murder rates have risen, in Chicago and elsewhere, even as protest about police behavior has become widespread.

Chicago had bad homicide years in 2008 and 2012, but the real problem in that city started after 2014. The homicide rate rose to more than 17 per 100,000 in 2015, and then spiked to 27 per 100,000 in 2016. The high murder rate of 2016 was accompanied by a clearance rate for homicide that fell below 30 percent. (The clearance rate is the share of murders that lead to a criminal charge; historically, it has been greater than 60 percent in the United States.) Since 2017, Chicago has hired more detectives, and the city’s clearance rate has risen to over 50 percent. Homicide rates for 2019 fell to 2015 levels.

Yet all is not well within the Chicago Police Department. As of the end of last year, the CPD is operating under a consent decree intended “to put in place reforms that govern police training and policies and provide officers the support they need to implement safe and constitutional policing practices.” The department accepted the decree “after months of negotiations,” following a lawsuit launched by the Illinois Department of Justice that charged the force with civil rights violations.

Perhaps the consent decree can make Chicago’s policing more effective. Good policing works with—not against—the community, and if large communities are angry with the police, something is probably wrong. Still, when police are demonized, they often pull back from troubled neighborhoods, worried about provoking conflicts. After protests following the funeral of Freddie Gray in Baltimore, arrests plummeted, and crime spiked. Lower crime rates and better community relations require, among other things, adequate resources. Communities can’t expect to cut spending on safety and not see rising crime or tougher tactics, or both. Police are typically tougher when they feel less safe, and they feel less safe when they have fewer resources.

According to the Mapping Police Violence database, police killed 259 African-Americans, of whom 28 were clearly unarmed, in 2018. Those are bad numbers, but those lives lost are a small share of the 7,407 African-Americans violently killed during that year. All human beings deserve safety, and safety depends on effective policing.

Cities have long been disease-spreading machines. They are nodes of the global trading network, which enables disease to spread across continents, as well as dense masses of humanity, which enables sickness to move rapidly within the urban area. The most important improvement in city life over the past 150 years was the drastic reduction in the frequency of plagues. The emergence of Covid-19 returns us to the dark history of urban contagion.

In 431 BC, Pericles brought the population of greater Athens within the city’s wall for protection against Sparta’s armies. The density may have brought safety from those fearsome hoplites but not from invisible pathogens that came by sea. The Plague of Athens, which had started the previous year, ravaged the overcrowded, unsanitary city. The outbreak may have killed one-fourth of Athens’s population, as well as leading to the city’s ultimate defeat in the Peloponnesian War and its eclipse as a great Mediterranean power.

One thousand years later, an even deadlier pandemic swept Constantinople, probably originating from the mountains of Central Asia. The Plague of Justinian was caused by the Yersinia pestis bacteria, carried by fleas and, in turn, by rats. A crowded imperial capital with close links to the outside world is particularly vulnerable to contagion. Yersinia pestis would inflict the medieval Black Death and continue to slaughter Europeans through the Great Plague of London in 1666.

The combination of globalization and urbanization only increased the risk of pandemic. Cholera had attacked the Ganges Delta long before 1817, but when transportation linkages were weak, the disease stayed local. By 1818, the world had become more connected. Some combination of Hindu pilgrims and British travelers appears to have helped cholera spread throughout south and east Asia. Ten years later, during the second cholera epidemic, the disease made it to London, Paris, and the Americas. A third epidemic reached New York City in 1849 and killed, among tens of thousands of others, my great-great-great-grandfather.

John Snow, the founder of epidemiology, lived during that third epidemic. His “Ghost Maps” enabled him to determine that the epicenter of the London outbreak was a well. His hypothesis that cholera was waterborne was supported by the low disease rates among workers in a local brewery, who mostly drank stronger stuff. Snow’s discovery helped build consensus for the investments in water pipes and sewers that massively reduced mortality rates in American cities.

There were signs that the public sector had been backsliding on urban health before the Covid-19 outbreak. The declining industrial city of Flint, Michigan, tried to reduce its water costs by cutting maintenance spending. When century-old lead pipes are not maintained, they become dangerous, and that’s what happened in Flint. Many of America’s declining industrial cities have aging infrastructure and limited finances, so the Flint water crisis may repeat itself elsewhere.

But the far more dangerous public-health threat to cities comes from airborne water droplets, not water pipes. After all, water can be purified. The spread of airborne disease can be prevented only by vaccination, effective treatment, or adequate distancing between human beings, created by physical space or other barriers. When neither cure nor vaccine is available, protection from airborne pandemic is incompatible with true physical density. The social distancing recommended as the response to Covid-19 was essentially an attempt to unravel urban America. The enormous economic dislocation that distancing has caused underscores the tremendous economic benefits of proximity.

Will Covid-19 permanently reshape urban America? The influenza pandemic of 1918–20 did not. Millions died, and death rates were significantly higher in urban areas, though thousands also died in rural areas. Yet when the pandemic ended, cities continued to grow. America’s urbanization rate rose from 51 percent in 1920 to 56 percent in 1930. The pandemic was a temporary calamity, not a permanent scourge.

Over the last century, medical technology has improved so much that contagious diseases seemed like much less of a risk. When the same H1N1 strain of influenza that appeared in 1918 threatened the world again in 2009, during the swine flu epidemic, the response was to use vaccination rather than quarantine. Until 2020, it seemed almost unthinkable to most Americans that a pandemic could shut down face-to-face interaction.

Unfortunately, we have no antidote yet for the variants of the severe acute respiratory syndrome (SARS) coronavirus that first appeared in China in 2003–04 and has now resurfaced, in altered form, with Covid-19, first identified last December in the Chinese city of Wuhan. The original SARS, like Covid-19, was associated with extremely fast rates of transmission, sickening many health-care workers. Covid-19 has had a bigger impact than SARS because China is far wealthier and more integrated into the global economy than it was in 2003, so the virus’s spread was more extensive.

Why was America’s urban resurgence of recent decades followed by so much unhappiness? Urban discontent today reflects the shortcomings of the political city, not the weakness of the economic city. The success of private enterprise in cities has not been matched by an enhanced public capacity. Effective governments can reduce the downsides of density; weak governments choose the apparently easier path of trying to limit growth rather than ameliorating its negative consequences. America’s public sector has too often used its regulatory power to limit urban change, instead of investing to enhance the experience of living in a shifting urban world.

Political progress in the twentieth century replaced corrupt but dynamic urban machines with city governments that were far more accountable to current residents, far more law-abiding—and far more resistant to change. Though corrupt, the machines were nevertheless entrepreneurial enterprises that welcomed new businesses, encouraged new construction, and provided services to constituents. The more honest governments of today are bureaucracies that follow—and enforce—existing rules.

At their best, cities are ladders for individuals and for society as a whole. Cities welcome poorer migrants and transform them into middle-income urbanites. Cities educate their young—both in schools and at work. Cities create fertile environments for cultural and political movements. But cities operate best with effective governance. Better urban schools seem like the most plausible method of promoting upward mobility in cities, for example. Yet teaching disadvantaged kids comes with intrinsic challenges, and when the political system’s rules protect the interests of teachers’ unions over those of children, necessary reforms get stymied. The entrepreneurship that might employ less educated urbanites is hamstrung by regulations that reduce competitive threats to existing businesses. Unfettered new construction is the surest path toward housing affordability, but new construction gets blocked by community activists. The original building codes, imposed in the nineteenth century, were intended to stop the spread of contagious disease. Over time, they morphed into tools for stopping any construction. We need a public sector that can improve its basic functions, like education and regulation and public health, to meet twenty-first-century needs—and one that can anticipate the pandemics of the future.

The urban-reform movements of the nineteenth century provide a model for how the public city can catch up with the private city. Between 1790 and 1860, New York City’s population grew from 33,000 to 813,000. Yet despite the city’s obvious success, it was a place of discontent and disorder. New York would improve in the decades ahead because leading New Yorkers collectively invested in their city. Their efforts provide a plausible model for making cities more livable today.

In 1860, New York was an economic juggernaut, with growing industries and a port that dominated the Atlantic seaboard. Yet the city was poorly run. Its mayor, Fernando Wood, was known more for corruption than competence. The state legislature, for example, tried to replace the police force that Wood controlled with a new, independent force; the two groups warred, and chaos reigned. Death rates also were far higher during this time than they had been before 1830, despite the Croton Aqueduct’s construction, because population density had risen and cholera was lethal, but tenement owners and poorer urbanites were unwilling to pay the cost of connecting to the system.

From 1860 to 1930, though, New York City became a far better place, thanks to the efforts of prominent reformers, working inside and outside government. Stephen Smith is one of New York’s sanitation heroes, a Bellevue Hospital doctor and the first leader of New York’s Metropolitan Board of Health. His achievements depended on the support of many civic leaders. When Smith tried to sue tenement owners into upgrading conditions, William Cullen Bryant, the poet and editor of the New York Evening Post, joined his cause. The New York Citizen’s Association, founded by leading civic businessmen, sponsored Smith’s hygiene research.

Smith had coauthored a report in 1865 documenting New York City’s sanitation shortcomings. By exposing the terrible conditions, the report made the case for sanitation laws, including a requirement that landlords provide clean water by connecting to the Croton system. The reforms, once enacted, delivered not only these regulations but also a board of health with the power to enforce them. The board was run by doctors, not politicians, and it became the city’s public-health authority. During a period of plague, a sanitation autocracy can make sense.

Another great reformer, Peter Cooper, made his fortune in real estate, manufacturing, and insurance. He had a hand in many of the battles to improve the city, including Smith’s, but his greatest legacy is Cooper Union. He wanted a school that would teach vocational skills for all, and he dedicated his fortune to that end. Cooper Union has thrived for more than 150 years, remaining tuition-free until 2014. Cooper’s private institution may provide a better model for low-cost vocational training in the twenty-first century than do our urban public schools.

Theodore Roosevelt pursued municipal improvement as a reforming police commissioner under Mayor William Strong in 1895. Strong also brought in the remarkable George Waring to clean up the city’s fetid streets. Waring, like Smith before him, brought an authoritarian approach to hygiene: if a cart blocked his street cleaners, he would remove the cart.

Improving New York took decades. It took public spending, but even more importantly, profound investments of time, effort, and cash from some of the city’s most capable citizens.

Even before Covid-19, cities were under strain in America. While many urban economies flourished, urban governments appeared stuck. A pandemic makes the weaknesses of those governments even costlier. If cities must enter lockdowns regularly, urban economies become unworkable. Leisure, hospitality, and retail trade provide 20 percent of America’s jobs and the leading urban employment opportunities for those with less formal education. Those industries can’t function when face-to-face contact is forbidden.

We don’t know how future pandemics will be thwarted—but if our urban world is to survive in its present form, they must be thwarted. It is not yet clear what combination of vaccines, health screening, or other measures will be necessary. I am sure that the effort should not—cannot—be left to the government alone. Making our twenty-first-century cities safe will require the same level of passion and competence that Stephen Smith and others brought when they fought to make the nineteenth-century city safe and successful.

Top Photo: New York, after a night of widespread looting: the city triumphant has become the city discordant. (ANDREW CRIBB/ALAMY STOCK PHOTO)