Category Archives: Economics

In 40 years, will self-driving cars send us packing for the suburbs?


At the end of 2013, the journal Cityscape put the following statement to contributors and asked their opinion of it: “In 40 years, the average person will live closer to her neighbors and farther from the ground than she does today.” This is a critique of one response. More to come…

Most urbanists will tell you that we’ll be living at higher densities sooner than you think. Nathaniel Baum-Snow, an economist at Brown University, is one of them. He cites a handful of reasons why he thinks we’ll all be living closer to our neighbors 40 years from now, including commute times, declining fertility rates, and stalled highway construction. Baum-Snow makes valid points, but many of his assumptions presume that the world 40 years from now, at least technologically, will look similar to today. Given the last 40 years, I’ll be surprised if that happens.

Self-driving cars are one of the biggest threats to the future of cities, and widespread adoption could single-handedly undermine one of Baum-Snow’s most compelling arguments—commute times, which he says will be a driving force behind increasing urban densities. As incomes have risen for many city dwellers—those in the top 50 percent, at least—the value of their commute time has also risen. Given Marchetti’s constant, which says that commute times tend to hover around 30 minutes each way, snarled traffic will force the wealthy out of the suburbs and back to cities. In a sense, we’ve already started to see that.

But self-driving cars could reverse that trend. As people’s commutes are freed up for other tasks, including work, they’ll stretch their daily trips, once again allowing them to live where they want. And as we’ve seen, people want to live where they have more space.¹ Compounding the problem is the fact that most early adopters are likely to be wealthy, the same people Baum-Snow says will be looking to drive less.

Working in cities’ favor, Baum-Snow adds, are declining fertility rates. Between 1967 and today, birth rates have fallen from 0.122 births per woman of childbearing age to 0.065, nearly a 50 percent drop. With people having half as many children, the need for space should decline. But as we’ve seen, that’s not necessarily the case. Between 1973 and 2012, median home sizes have grown from 1,525 square feet to 2,306 square feet, the same time that fertility was declining. In that same time period, median household income has risen almost $10,000 when adjusted for inflation, a nearly 25 percent increase.²

Then there’s the siren song of the suburbs—school quality. Suburban and small town school districts frequently outperform their urban counterparts. Baum-Snow notes that the quality of public schools in big cities has stabilized, at least, but that isn’t quite the same as improving. Plus, even if they do improve, urban schools will have to overcome the stereotype wrought by decades of poor performance.

(There is a simple fix, of course—invest in public education at all levels. Early childhood programs have shown great promise at preparing children of all backgrounds for full-time school, and education is the best chance many of children have to break free of poverty.)

Given these realities, I don’t think the future points to downtown, as Baum-Snow does. It’s true that city centers are the hot place to be, but density numbers don’t reflect the newfound enthusiasm. And trends in technology could shatter the many cities’ recoveries.

Despite that, I think many of us—at least, those of us not in the top few percent—will be living closer together. Not downtown, but in the sprawling inner suburbs that will be indistinguishable from the rest of the city, slogging through long commutes between home—which was convenient to the old job we got laid off from—and our new jobs on the wrong side of town.

  1. Home sizes briefly halted their inflation during the recession, but they’ve started to rise again.
  2. On top of that, interest rates are lower today than in the 1970s. That could change 40 years from now, of course.

Photo by Michael Colburn.


Baum-Snow, Nathaniel. 2013. “Changes in Urban Population Densities Over the Next 40 Years.” Cityscape 15(3).

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In 40 years, will we live in cities in the sky?

Marchetti’s constant, or why the 30 minute commute is here to stay

Population density fostered literacy, the Industrial Revolution

How to save a dying city


Forty years ago, Detroit was doing pretty well. The auto industry was cranking, employment was high, wages were decent, and the city was packed. Today, well, not so much.

Forty years ago, Pittsburgh was doing pretty well. The steel industry was cranking, employment was high, wages were decent, and the city was packed. Today, well, it’s actually not doing so bad.

Both Rust Belt cities have a lot in common. They were heavily working class, and when manufacturing started moving overseas and automation encroached on what was left, people lost their jobs. When manufacturing jobs didn’t return, they left. Since 1970, Detroit has lost more than 45 percent of its population, Pittsburgh more than 43 percent. So what makes the two different?

Education, in a word. Today, a greater proportion of Pittsburgh’s residents have college or higher degrees compared with Detroit. That comparison comes by way of Dan Hartley, a Cleveland Federal Reserve economist, who crunched some numbers for four hard-hit Rust Belt cities—Detroit, Pittsburgh, Buffalo, and Cleveland—and arrived at some not-surprising conclusions. Though most of his analysis focuses on Cleveland, it was the disparities between Detroit and Pittsburgh that caught my eye.

In 1970, before the Rust Belt grew rusty, both cities were at the tops of their games. Median household income in Motor City was $46,438,¹ not far off from today’s nationwide median of about $51,000. For a working class city, that’s not bad. Pittsburgh was in good shape, too, with a median income of $37,477. Home prices were similarly competitive. In economic terms, both Detroit and Pittsburgh were typical American cities.

But over time the two diverged. By 2006, the year in which Hartley’s analysis is based, median household incomes were down 35 percent in Detroit but only off 10 percent in Pittsburgh. Home prices mimic that on a lesser scale, with Detroit up 9 percent and Pittsburgh up 13 percent. Where they differ is in education. In 1970, 6 percent of Detroit’s population had a college or higher degree. In 2006, just over 11 percent did. Pittsburgh, on the other hand, more than tripled its share, going from 9 percent in 1970 to over 31 percent in 2006.

In that time, the Steel City invested heavily in wooing healthcare companies and was reasonably successful at it. But that shift would have stumbled if the city hadn’t already had a strong educational foundation. Both Carnegie Mellon and the University of Pittsburgh are located in the city, providing plenty of local college grads looking for employment. Detroit has Wayne State, which is not a bad school at all, but it can’t compare with two, high-reputation schools like Carnegie Mellon or the University of Pittsburgh, which together have 12,500 more students than Wayne State.

If you look closely and in the right places, you quickly notice that education is the cornerstone of many booming cities and regions. Silicon Valley wouldn’t be what it is today without UC Berkeley or Stanford, and the Boston area wouldn’t be a hub of robotics if it wasn’t for MIT. If you want a thriving city, focus on education. I won’t say everything else is just details, but smart people have a way of figuring those out.

  1. All figures are in 2009 dollars.


Hartley, Dan. 2013. Urban Decline in Rust-Belt Cities. Economic commentary, Cleveland Federal Reserve Bank.

Photo by migee_castaneda

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How to keep the economy growing when our population is not


Zero population growth is a period in future human history that is both hoped-for and feared. If we don’t get to that point, the world could literally become overrun with humans, straining already taxed resources like fresh water and farmland to the breaking point. But with zero population growth, the global economy—heavily reliant on a young and expanding workforce—could collapse. No matter what we hope, according to projections by the United Nations, it’s likely that within the next century, the global population will level off or even shrink.

It’s a prospect that vexes demographers and economists alike, which is a sharp change from the 1960s, when we feared rampant population growth. Now, we fret over the opposite, and for good reason. While stabilizing or declining numbers will certainly ease the burden on the environment, no one knows how society will function in a future with fewer people. Globally, it’s never happened before. Locally, we’re starting to see it in some countries such as Japan, which has been stuck at about 127 million for the last decade. By 2045, it will drop to 105 million, and it’s already affecting Japan’s long-term thinking—some economists are questioning the need for the country’s proposed maglev system if there are fewer people to ride it.

There’s another, more fundamental problem that zero or negative population growth poses, though—the transfer of knowledge. We know that when people come together, they tend to create new technologies, skills, and knowledge. Cities are hubs of innovation, universities are great factories of scholarship, and even smaller groups can inspire people to create wonderful things. Perhaps more importantly, the number and strength of our connections are vital for passing knowledge on to others, two recent studies suggest. Without those connections, our society could fall rapidly behind. Fortunately, the research also suggests a way to escape the declining population trap.

Ed Yong, who covered the two studies for Nature News, pointed out that the papers provide independent validation of the idea that cultural knowledge is tightly correlated with group size and connectedness. They approach the problem from slightly different angles. The first study examined whether group size affected how well cultural tasks—in this case making an arrowhead or a fishing net—were passed down from one group to the next. In every instance, groups of eight or 16 performed significantly better than groups of two or four. Bigger groups also developed better and quicker ways of making the arrowheads.

The second study tested how interpersonal connections affected performance of a task, in this case either duplicating an image on a computer or recreating a series of knots used in rock climbing. In the drawing experiment, which tested the creation of knowledge, inexperienced people started off, going by trial and error. Later generations of participants could watch earlier people’s attempts and use that to hone their skills. Some were given the opportunity to observe five different attempts, others were only given the chance to see one. Those who had access to five examples recreated the drawings more accurately than those who could only see one.

The knot-tying experiment tested how cultural knowledge was maintained. The first generation of participants was trained by an instructor. Later generations watched footage of previous people tying the knots. Those who could watch five examples were twice as good at tying the knots as those who could only watch one example. The more connections, the more faithfully that knowledge was passed on.

Together, these two papers make a strong case for social savvy being the foundation of our complex culture. The first paper—the one with the arrowheads and fishing nets—confirms experimentally what many scientists suspected, that larger groups are both more proficient and more innovative. But the second study really intrigues me. It’s the one that, I believe, offers a way to keep our economy surging when our population begins to level off or decline.

The key to that is social connections. The more connected people were in either experiment of the second study, the better they performed, whether that be for maintaining knowledge or advancing it. Following that thread, it stands to reason that we can successfully decouple economic growth from population growth if social connections continue to increase. So even if our numbers decline, as long as our connections do not, we will at the very least be able to maintain our cultural knowledge and hopefully our standard of living.

To do that, we need to meet three challenges. First, the trend toward urbanization needs to continue. Cities foster connections between people, and the more people that live in cities, the more cultural knowledge we can maintain. Second, the internet needs to be everywhere. As the internet has taken hold, it has connected people in ways never before imagined. It’s now easier to access scholarly articles, stay in touch with friends and family, and partner with peers around the globe, all of which serve to maintain and increase our collective knowledge. Finally, as cities swell, we need to make sure they are physically connected as seamlessly as possible. Large cities can provide a wealth of opportunities, but no single city can offer them all. Being able to zip from one to the next will be vital for our cultural survival.¹

If we can meet those three challenges, and if social connections continue to multiply as population stabilizes or declines, then I think we’ll have a good chance of maintaining economic growth and raising standards of living.

  1. I would argue that this implies that Japan’s maglev system will be even more important if the population declines as is predicted. They’ll need more connections, not fewer.


Derex M., Beugin M.P., Godelle B. & Raymond M. (2013). Experimental evidence for the influence of group size on cultural complexity, Nature, DOI:

Muthukrishna M., Shulman B.W., Vasilescu V. & Henrich J. (2013). Sociality influences cultural complexity, Proceedings of the Royal Society B: Biological Sciences, 281 (1774) 20132511-20132511. DOI:

Photo by eioua

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The uncanny valley of commerce, and what it means for your community

■ target

Your grocery store. Google. Target. What do these three have in common? They all gather personal information, and they all do it—and I’m paraphrasing here—”to serve their customers better.” In the case of your grocery store, they profile your habits to get you in the store, to buy more things. Same with Target. Google mines your personal information to hit you with ads you’re more likely to click on. In each case the company is looking to make money off their knowledge of you. It’s not that different from the way business used to be run. With one big exception.

In the past, when you visited a store, you may have known the owner. The owner of the hardware store knew you were a repeat customer, so he may have given you a deal on a new drill, knowing you’d probably be back for screws, lumber, and glue. Or maybe the owner of the shoe store, which you’d been shopping at for years, would cut you a deal on your kid’s new sneakers. In each case, they wanted to keep you as a customer. Your repeat business ensured future revenue, which is more valuable than a few extra dollars today.

Big businesses know this, too. They know that repeat customers are among the most profitable—that’s why there are frequent flier programs, club memberships, and loyalty cards. But somewhere along the line, they also realized they were sitting on a treasure trove. With every signup, with every logged purchase, people gave away personal information that hinted at what kind of customer they were. Companies started to mine that data, looking for patterns that would reveal even more intimate details. Target is perhaps best at this among large retailers, famously predicting their customers’ pregnancies weeks before they even know.¹

And therein lies the problem. Massive databases of personal information allow companies to do the same things businesses did in the past—offer deals to loyal customers, personalize offerings, and so on—but they do so without any sort of meaningful relationship. “Steve” may be genuinely interested in your budding family. Target is not, except to sell you more diapers. These companies are able to do make personal offerings, but in such a way that it’s clear no human is behind them. Call it the uncanny valley of commerce.

In commerce, though, relationships matter. That’s part—a large part, I’d argue—of what makes us queasy about data mining. Personalized deals are one thing when someone you know is offering them. But in the absence of a person we know, we don’t know what’s behind the gesture. Without a personal relationship, we can’t trust that these companies have our best interests in mind.

Now, things weren’t all sunshine and daisies in the past. Small operators used to disappear in the middle of the night, absconding with their customers’ money.² And while personal relationships can keep some vendors in line, it holds little meaning for others. It’s true that big companies can be held more accountable in many circumstances, but that doesn’t mean we trust them any more. There’s a reason they’re called “faceless corporations.”

Massive multinationals exist because of economies of scale, which has been shifting our economy from one driven by small proprietors to one dominated by large companies. It’s also changing the relationship between seller and buyer. And just as economies of scale have transformed businesses, they’ve also fostered population growth. The two go hand-in-hand. Because we’re now so numerous, we’re easier to deal with in bulk than one-on-one. But I suspect that transformation is also subtly altering our communities, displacing some of the relationships that were built around proprietors and customers. It’s not clear to me what’s taking their place.

There will always be opportunities for small businesses. How many? We don’t know. But there are certain to be fewer. Personal relationships in commerce will continue to wane, and I’m guessing it’ll have an enormous impact on our lives, our finances, and our communities.

  1. Charles Duhigg exposed some of Target’s secrets in his book The Power of Habit, an excerpt of which you can read online.
  2. Though truth be told, the same thing can happen today. It’s called bankruptcy.

Photo by Mr. T in DC

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Keep your eyes to yourself

What’s more energy efficient, shopping online or in stores?

■ fedex-truck

Back in 1998, in the heyday of the dot-com bubble, launched. The site was perhaps best known for its ad campaign which featured a sock puppet dog. The company’s business plan was to deliver pet supplies to people’s homes. The site was a horrendous failure, and its bankruptcy served as a sort of warning sign to would-be e-commerce entrepreneurs for years to come.

Yet if we fast-forward to today, home delivery of everyday items seems, well, everyday. may have had a flawed business model, but the basic principle behind it was sound. Amazon weathered the dot-com bust, as did a handful of other e-commerce sites. Many brick-and-mortar retailers have successful websites. Even trips to the grocery store are being replaced with deliveries from companies like Peapod, FreshDirect, and even Amazon.¹ But with the boom in online shopping for everything from jeans to Jujyfruits, people have grown concerned that e-commerce’s simplicity comes with an environmental price.

The concern mostly centers around the delivery’s carbon footprint. All those UPS trucks rumbling down every street in American surely can’t be a good thing. They’re big, their loud engines must suck tremendous amounts of fuel, and what happens if you’re not home to pick it up? Fret not. Your Amazon delivery probably has a trimmer footprint than a simple trip to the store.

A number of studies have looked at the difference in carbon emissions between items ordered over the internet and those purchased the old fashioned way.² One straightforward study collected data from a clothing retailer in Germany that sold their wares both in stores and online. Researchers surveyed over 700 in-store shoppers at two locations and 40,000 online orders. They then stratified their results based on travel distances to the store and distances from the warehouse to customers’ homes. At short distances—less than 8.6 miles or 14 km one-way—in-store shoppers slightly edged out online customers per transaction, about 73.8 g CO2 vs 77.9 g CO2. But over that, online shoppers’ footprints remained relatively stable while store goers emissions skyrocketed to as high as 451.4 g CO2 per transaction if they had to travel over 62 miles or 100 km.

Another more comprehensive study from the U.K. looked at the “last mile,” or the last journey of an item to a customer’s home. Researchers focused on non-food items, such as books, CDs, clothing, cameras and other household items. They also took into account how a person traveled to the store—car, bus, walking, or other public transportation—the frequency with which items are returned, and how requiring signatures for packages affects the rate of successful deliveries.³ If you want to reduce your carbon footprint, their results were unequivocal: Shop online. If you drove to the store, you’d have to buy 24 items to make the trip equal to the carbon footprint of just one item ordered online. If you took the bus, you’d have to buy eight.

Why are brick-and-mortar stores so inefficient? It turns out that transporting people to the store to select something and then getting them back home again requires a lot of energy. You also have to consider that items sold in stores were distributed from a central warehouse. When you place an order online, that trip transforms from one to the store to one directly to your home. Plus, delivery services optimize their routes to waste the least amount of fuel. Everyday shoppers don’t think in that level of detail. Even if you combine trips, which many of us are terrible at doing, you’d have to buy a lot of stuff per trip to equal the efficiency of a delivery.

  1. I subscribe to a monthly delivery of cereal from Amazon—it’s cheaper and one less thing I have to worry about at the store.
  2. Most of them considered European consumers, so you can assume that whatever inefficiencies are racked up for in-store purchases can be inflated for American consumers, who use less public transit and have less fuel efficient vehicles.
  3. Requiring signatures decreases the first-time delivery rate substantially, from as low as 2 percent for no signature to as high as 30 percent with a required signature.
  4. UPS’s famous “no left turns” rule is a testament to that.


Edwards J.B., McKinnon A.C. & Cullinane S.L. (2010). Comparative analysis of the carbon footprints of conventional and online retailing: A “last mile” perspective, International Journal of Physical Distribution & Logistics Management, 40 (1/2) 103-123. DOI:

Wiese A., Toporowski W. & Zielke S. (2012). Transport-related CO2 effects of online and brick-and-mortar shopping: A comparison and sensitivity analysis of clothing retailing, Transportation Research Part D: Transport and Environment, 17 (6) 473-477. DOI:

Photo by lordferguson.

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Mo’ money, mo’ parks

Fujigaoka Park in Yokohama

Which came first, the park or the rich people?

It’s a poorly kept secret that real estate is more expensive near parks. They’re like magnets for wealth. But is that the whole story? Certainly wealthy people are attracted to parks—just look at many of the neighborhoods around Central Park in New York City. But what about new parks? Are they preferentially cited in wealthier neighborhoods, either because residents have more clout or developers are more willing to cede land to attract deep pockets?

Shinya Yasumoto and colleagues decided to tackle that question in Yokohama, Japan, a city of 3.7 million just outside of Tokyo. They tallied the number of parks that existed in 1988 and those that were opened from then until 2005. They also noted park size, accessibility, and neighborhood characteristics such as property values, resident incomes, housing characteristics, environmental quality, and other amenities, including schools and transit. They also indicated whether a park was set aside by the city or by a private developer.

What they found shouldn’t be surprising, but it should be cause for alarm. The city opened more parks than developers—556 compared with 472—and the total area of new city parks was substantially larger than those set aside by developer—1,702 hectares vs. 212 hectares. When the city opened a new park, it tended to be relatively equitable in terms of size and placement. Poor neighborhoods were almost as likely to receive a new park as richer ones. (Almost. The city wasn’t entirely immune from wealth’s influence; it did open slightly more parks in wealthier areas.)

Developers, on the other hand, clearly favored citing new parks in well-to-do neighborhoods. They added 117 hectares of parkland across 125 parks in the most affluent communities, but only 20 hectares across 59 parks in the least affluent. Furthermore, Yasumoto and colleagues note, the wealthiest areas had the best access to parks throughout the 18 year study.

The study was limited to Yokohama, one city in Japan. It’s possible that cities in other parts of the world don’t follow the same trend. But I’d be surprised if it didn’t. In hundreds of cities across thousands of years, parkland has been one of the many trappings of wealth.

Still, that doesn’t mean the situation is hopeless. Yasumoto and colleagues point out that a neighborhood’s demographic change lags behind park openings. So while it’s true that opening a new park will raise property values—potentially pushing out the poor—it won’t do so quickly enough to outweigh the benefits of new open space.


Yasumoto, Shinya, Andrew Jones, and Chihiro Shimizu. 2013. “Longitudinal trends in equity of park accessibility in Yokohama, Japan: An investigation of the role of causal mechanisms.” Working paper.

Photo by dakiny.

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We all want to live in small towns, and it’s killing cities

Downtown Northfield, MN

A bunch of economists and a blogger are trying to dissect the riddle of why metropolitan population density has fallen in the United States. Robert Shiller (yes, that Robert Shiller) seems to have unknowingly kicked off the whole thing when he wrote an essay a few weeks ago in which he said housing prices have actually been pretty stable when you adjust for inflation.

Bill McBride took issue with that, essentially saying that because land is scarce in cities, the value of the land (and the homes on it) should go up. Noah Smith didn’t quite agree with McBride, arguing that changes in transportation cost—everything from automobiles to telepresence—will counter the effects of population density over time, which is why house prices should remain flat. Paul Krugman jumped in and sided with Smith, mostly, citing the issue of declining metro population density across the United States.

Then Felix Salmon, the blogger, entered the picture. He wrote a post a few days ago laying out his solution to the riddle of why metro population density is declining. Rich people, he says, are moving to the city in larger numbers, and because they can afford more space, urban population densities are either holding steady or falling. That’s been pushing less wealthy people out to the suburbs and beyond. I’m skeptical that’s the real reason.

Most of the previous decade’s growth in the U.S. happened in the exurbs, those far flung outposts on the fringes of metro areas. There, populations rose by about 5 percent, much higher than the zero to 2 percent elsewhere throughout metro areas, including low-density but closer-in suburbs. People forgoing suburbs for the exurbs—that’s a nuance of the statistic that makes me question Salmon. If people are being driven out of the city because of high rents, then the suburbs should be growing swiftly, too. But they’re not—at least not as much as the exurbs.

Rather than reacting to what the rich are doing in the city, I think it’s more the result of how most of the rest of us would like to live. The exurbs are closer, by many measures, to the small town American ideal than the city or even the suburbs. Exurbs have single-family homes, big lots, wide streets, and a nearby countryside. The city doesn’t have that, and many suburbs don’t anymore, either—as cities swell, they’re becoming indistinguishable from the city. The exurbs are the new suburbs.

Krugman tries to drive home his point, saying, “the average American lives in a quite densely populated neighborhood, with more than 5000 people per square mile.” As such, he says, “real” America isn’t a small town, but rather something like metropolitan Baltimore. By pure statistics, he’s right. But that doesn’t necessarily mean the U.S. is a country trending toward Baltimore. A statistical snapshot can’t outweigh decades of cultural legacy. Most Americans may live like Baltimoreans, but do they want to?

Our cultural tendencies suggest we don’t. As long as the American ideal is to live in a small town—which to many people¹ means big yards, small downtowns, and concomitant low population densities—then that’s where we’re heading as a nation. If cities are to succeed, maybe they need to look to small towns for inspiration. Not the low densities—it wouldn’t be much of a city, then—but the more abstract qualities that draw people to them.

  1. Not necessarily me, though that’s a post for another time.

Photo by Northfielder.

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Why neighborhood quality matters


In the summer of 2008, I found myself lost in Chicago. I was new to the sprawling city, living there for two months while working as an intern science reporter at the Chicago Tribune. To counter weekend boredom, I would explore the city by bike. I’d often find myself mildly disoriented, but this time I had really done it. I knew I was north of the Loop, but that was about it.

Finally, I happened across Halsted Street, a major north-south thoroughfare that ran a few blocks from where I was living. Relieved, I started south, coasting past nice brick apartment buildings and row houses, big box stores and tony shops. But after a few miles, the timbre of Halsted changed. Quickly. Well-kept storefronts gave way to crumbling industrial buildings and weedy sidewalks. Then came the most depressing hulk of a building you could imagine. It was a drab beige tower surrounded by acres of asphalt and dotted with boarded up windows fringed with smoke stains. I knew exactly where I was.

Cabrini-Green’s bad reputation was well-known, especially in the Midwest where I grew up. It was among the first projects built by the Chicago Housing Authority in the mid-20th century. By the 1970s, Cabrini-Green was notorious for destitution and violence. Gangs had taken over various buildings, and internecine warfare kept even the hard-nosed Chicago police at bay. Tales of horrific murders spread around the country. My aunt, who tutored elementary school students there, would recount stories she heard from residents. Cabrini-Green was at best a place to be avoided.

And here I was, blithely riding by. Though I didn’t know it at the time, Cabrini-Green’s most notorious days were past it. The tower was largely vacant, save for a few holdouts. When I moved back to Chicago a year later, the last of the high-rises were being torn down.

Housing projects are widely viewed as a failure. Their concentrated poverty seemed to descend into a negative feedback loop, where depravity fed on itself. Over the years, Chicago tried to assert control, to no avail. They muscled up the police presence; that was met with sniper fire. In 1981, then-mayor Jane Byrne moved into a ground floor apartment guarded round the clock by uniformed officers. She moved out three weeks later.

Oddly enough, Byrne’s publicity stunt was on the right track, if completely backwards. Housing projects’ needed a shock to break the cycle. But they didn’t need a mayor moving in. They needed to move people out.

That’s exactly what the United States Department of Housing and Urban Development did in the mid-1990s, when it took over the dysfunctional Chicago Housing Authority. As a part of the Moving to Opportunity program, households could enroll in a lottery which would give winners assistance in finding and vouchers to pay for housing in low poverty neighborhoods. Chicago wasn’t the only city in the trial—New York, Boston, Los Angeles, and Baltimore were also involved. The idea was that after moving to low poverty neighborhoods, families would find more and better jobs and be healthier and happier. Nearly 5,000 families were included in the experiment.

It worked, to some extent. A study published today in the journal Science details how people involved in Moving to Opportunity have fared in the 15 years since the program started. Though those who moved to low poverty neighborhoods were still as poor as those who didn’t, there were some changes. Notably, they were happier and somewhat healthier.

The study, led by Jens Ludwig of the University of Chicago, looked at a variety of factors, ranging from poverty rate to racial segregation to mental and physical health. Though poverty rates didn’t change significantly, and racial segregation nudged only slightly lower, people’s health improved. Physical health, as measured by obesity and diabetes, were slightly better in this study. (A prior study published by Ludwig and colleagues in the New England Journal of Medicine last year reported more significant improvements.) But mental health, as measured by self-reported subjective well-being, or how people felt about their lives, was significantly improved among people who lived in low poverty neighborhoods. So while people were still poor, they were happier. That says a lot about the importance of your surroundings.

Ludwig and his colleagues point out that if the objective of Moving to Opportunity was to reduce poverty, then at this point it would be considered a failure. But if the goal was to improve people’s lives in other ways, well, it’s not doing too bad.

The study only focused on adults, in part because measuring subjective well-being of youngsters is an inexact science. Because of that, they’re missing an important component. It’s difficult to break free of poverty, especially when you’ve inherited it. But children, through better education and improved health, have more potential than their parents (even if that’s only because they have more of life left to live). It’s possible that, because of a more positive home life, kids in families living in low poverty will have better opportunities than their parents, helping them break the cycle.


Ludwig, Jens, Greg J. Duncan, Lisa A. Gennetian, Lawrence F. Katz, Ronald C. Kessler, Jeffrey R. Kling Lisa Sanbonmatsu. 2012. “Neighborhood Effects on the Long-Term Well-Being of Low-Income Adults”. Science 337(21): 15051510. DOI: 10.1126/science.1224648

Photo by puroticorico.

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Your images of income inequality, seen from space

A month ago, I covered a study showing how tree cover was related to income level. A couple of weeks later, I posted images gleaned from Google Earth showing how easy it is to spot income inequality from space. I also asked you, my readers, to send me more examples of the same.

The response has been overwhelming. In fact, I’m still receiving emails and comments. I haven’t been able to go through them all, so if yours isn’t below, hang tight. I’ll get to it eventually. Consider this a post that’ll be updated continuously. As they say, check back early and often.

So without further ado, here they are. This is where you see income inequality. You may see it every day, right in your own backyard. You may have stumbled across it years ago. You may have noticed on a vacation. But collectively, you see it everywhere. Keep ’em coming.

Mexico City

From Todd Gastelum, who writes:

Although it appears that these satellite images are presented at different scales, I assure you that they were not. The houses in Lomas truly are enormous whereas San Miguel Teotongo is typical of the dense, irregular urbanization characteristic of the city’s more peripheral zones.

Lomas de Chapultepec, Miguel Hidalgo

San Miguel Teotongo

San Miguel Teotongo, Iztapalapa

Lomas de Chapultepec

Dar es Salaam, Tanzania

From Aaron Krolikowski, who writes:

I’m a PhD student (in Geography) from the University of Oxford. My work takes place in Dar es Salaam, Tanzania and I spend quite a bit of time looking at maps of the city. One of the first things I noticed was exactly what you mention in terms of the ability to see income inequality from a birds-eye view. I’ve shared some photos with you to give you an idea of what I look at (and live!) every day here.

The first – To the left you have unplanned settlements of “Mikoroshini” and “Makangira”…to the right, the highly affluent and very European “Oyster Bay”

The second – To the left is the informal settlement of Hanna Nassif and across the river is middle-class Upanga

Mikoroshini, Makangira, and Oyster Bay


Hanna Nassif and Upanga



From Sylvian Paradis.

Downtown East Side

Downtown East Side

British Properties

British Properties

Lisbon, Portugal

From João Jordão.

Cova da Moura, Amadora

Cova da Moura



Why I can’t move back to Wisconsin


I’ve often wondered if I would ever move back to my home state of Wisconsin. It’s not the logistics that phase me—I’ve lived in California, Illinois, and Massachusetts in the last three years. No, I’ve wondered whether the state could lure me and my wife with promising and satisfying jobs to complement the state’s kind people and bucolic countryside. Yesterday, I learned that will never happen.

It was yesterday that Governor Scott Walker survived a recall election. The contentious recall was spurred by his decision to strip public employees of their collective bargaining rights, the majority of whom are teachers.¹ Walker sold the move as a way to balance the budget, but really he was just codifying the shift in Wisconsin’s values that has occurred over the past few decades. It also betrays Wisconsin’s uncertainty about how to deal with the future.

Wisconsin, like many rust belt states, has had a difficult time finding its economic footing ever since off-shoring became de rigueur among manufacturing companies. It’s had a few chances since then, but none more promising than the biotech opportunity that slipped through its fingers. The University of Wisconsin was a pioneer in stem cell research. Had George W. Bush not restricted funding for stem cell research, Madison could have been an incubator for related startups, enabling the state to shrug off its manufacturing past. It was a rare glimpse of an alternate future. The loss of that future should have galvanized public and private investments in education and research to unearth the next big opportunity. Instead, Wisconsin gave up. Frustrated, it turned to a simpler and shorter-term solution—tax breaks.

What the state really needs is a complete economic overhaul. Tax breaks won’t accomplish that. That’s not to say tax breaks don’t have their place. They can entice established businesses to relocate. They can encourage existing ones to hire a few more workers. They can even help fledgling businesses gain a foothold. But they won’t create the kind of daring and brilliant entrepreneurs needed to reshape Wisconsin’s economy.

No one ever started a revolutionary company because of tax breaks. Disruptive companies are founded because someone has a fantastic new idea, not because the state offered them a few thousand dollars. They succeed because they can hire intelligent, well-educated employees, not because they are paid to increase headcounts. Such transformative companies don’t magically appear because of low taxes. They bubble up in places that value education and innovation.

Wisconsin is a state adrift. Where it used to be an agricultural and manufacturing powerhouse, today it is neither. It has no defining industry, no discernible direction. Wisconsin is trying to rediscover its economic muse, but it’s going about it in all the wrong ways.

Wisconsin could still find its way by pouring money into education. That in turn would encourage the sorts of crazy innovation that happens across the street from places like Stanford and MIT. By offering its best and brightest more than just friendly faces and a low cost of living, it could keep them at home rather than lose them to other states. These changes won’t happen over night—Silicon Valley’s success took years, even decades, to manifest—but they could happen.

Yet I know they won’t. Deep down, I know I will never be able to move back to Wisconsin.

  1. Well, some public employees. Police and firefighters retain theirs.

Photo by CindyH Photography.

Income inequality, as seen from space

Last week, I wrote about how urban trees—or the lack thereof—can reveal income inequality. After writing that article, I was curious, could I actually see income inequality from space? It turned out to be easier than I expected.

Below are satellite images from Google Earth that show two neighborhoods from a selection of cities around the world. In case it isn’t obvious, the first image is the less well-off neighborhood, the second the wealthier one.

Rio de Janeiro


Rocinha, Rio de Janeiro

Zona Sul

Zona Sul, Rio de Janeiro


West Oakland

West Oakland


Piedmont, California (enclave of Oakland)


Fourth Ward

Fourth Ward, Houston

River Oaks

River Oaks, Houston



Hyde Park

Hyde Park, Chicago



Fengtai, Beijing


Chaoyang, Beijing

Boston metro area, Massachusetts

Ball Square, Somerville

Somerville, Massachusetts

West Cambridge

Cambridge, Massachusetts

Your examples

Do you have other cities or neighborhoods in mind? I’d love to hear from you. Send me an email with photos or link to your blog post. In the next couple of weeks, I’ll put together a follow up article that features your examples.

Be sure to include the names of the cities and neighborhoods you’re highlighting and if you’d like me to mention your name.


Your examples are now posted! The response to my call for examples has been unbelievable. I’ve received hundreds of messages. I have the first batch up, and as I have time, I’ll be adding many more. Keep ’em coming.

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Urban trees reveal income inequality

Income inequality in the Roman Empire

Ghosts of geography

Urban trees reveal income inequality

Street trees

Wealthy cities seem to have it all. Expansive, well-manicured parks. Fine dining. Renowned orchestras and theaters. More trees. Wait, trees? I’m afraid so.

Research published a few years ago shows a tight relationship between per capita income and forest cover. The study’s authors tallied total forest cover for 210 cities over 100,000 people in the contiguous United States using the U.S. Department of Agriculture’s natural resource inventory and satellite imagery. They also gathered economic data, including income, land prices, and disposable income.

They found that for every 1 percent increase in per capita income, demand for forest cover increased by 1.76 percent. But when income dropped by the same amount, demand decreased by 1.26 percent. That’s a pretty tight correlation. The researchers reason that wealthier cities can afford more trees, both on private and public property. The well-to-do can afford larger lots, which in turn can support more trees. On the public side, cities with larger tax bases can afford to plant and maintain more trees. Given the recent problems New York City has had with its aging trees dropping limbs on unsuspecting passers-by—and the lawsuits that result—it’s no surprise that poorer cities would keep lean tree inventories.

But what disturbs me is that the study’s authors say the demand curve they see for tree cover is more typical of demand for luxury goods than necessities. That’s too bad. It’s easy to see trees as a luxury when a city can barely keep its roads and sewers in working order, but that glosses over the many benefits urban trees provide. They shade houses in the summer, reducing cooling bills. They scrub the air of pollution, especially of the particulate variety, which in many poor neighborhoods is responsible for increased asthma rates and other health problems. They also reduce stress, which has its own health benefits. Large, established trees can even fight crime.

Fortunately, many cities understand the value trees bring to their cities. New York City is aiming to double the number of trees it has to 1 million. Chicago has planted over 600,000 in the last twenty years.¹ And London has been working to get 20,000 new trees in the ground before it hosts the Olympics.

But those cities are relatively wealthy. It’s the poorer ones that probably need trees the most but are the least able to plant and maintain them. The Arbor Day Foundation is a great resource in those cases, but like many non-profits, it is stretched too thin. Compounding the inequality is the fact that most tree planting programs are local. Urban forestry has sailed largely under the federal government’s radar. The U.S. Forest Service does have a urban and community forestry program, but is woefully underfunded, having only $900,000 to disperse in grants. Bolstering that program could help struggling cities plant the trees they need. After all, trees and the benefits they provide are more than just a luxury.

  1. Though like many of Chicago’s boasts that number was probably inflated by including replacement trees.


Zhu, P., & Zhang, Y. (2008). Demand for urban forests in United States cities Landscape and Urban Planning, 84 (3-4), 293-300 DOI: 10.1016/j.landurbplan.2007.09.005

Photo by Alex E. Proimos.

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Income inequality, as seen from space

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An office with a view

Office in the woods

There’s a scene in the movie Office Space where Peter, the protagonist, unscrews part of his cubicle and ceremoniously pushes the wall over, sending it and its shelved contents crashing to the floor. With a satisfied smile, he pats his desk a few times, kicks back, and enjoys his new view.

As I write this, the view out my window isn’t much more than Peter’s. Just a handful trees—no mountains, no idyllic nature scene, nothing that would make Ansel Adams jealous. Just one scrubby street tree and a couple of canopies poking their heads above the adjacent apartment building.

But according to Rachel Kaplan, an environmental psychologist, those few trees are far better than nothing at all. Kaplan has documented numerous cases in which workers reported feeling happier and more satisfied with their jobs because of the view they had out their window. Even views of parking lots—so long as they had trees or some other landscaping—were enough to brighten some people’s days.

Kaplan has made a career out of studying how views of nature affect various parts of people’s lives, from patient recovery times to worker productivity. Currently, I’m interested in her research on the latter topic. Staring out at a busy street is better than no view at all, but sometimes I feel antsy and distracted for no apparent reason. I’ve wondered if a more bucolic view would focus my efforts and lift my spirits. Coincidentally, Kaplan’s research suggests that’s exactly what would happen.

Kaplan says windows give people the opportunity for short restorative breaks. After hours spent staring at a computer screen or hammering through some repetitive task, a brief diversion or daydream is sometimes all that’s needed to push through the rest of the day. Allowing ourselves a short mental break boosts our happiness, which also increases our productivity.

But restorative breaks are more effective, according to Kaplan’s research, if they include gazing upon a natural scene. There’s something irreplaceable about nature. Not just greenery—office plants had a small positive effect, but one that paled in comparison to a natural view. Just adding a few natural elements to a windowful of buildings or parking lots raised employee satisfaction by a significant amount. Workers with nature views reported feeling less frustrated, more patient, and more satisfied with their jobs. Perhaps improbably, they also felt their jobs were more challenging and expressed greater enthusiasm for their work, despite the fact everyone surveyed had relatively similar jobs. Furthermore, workers with nature views also reported fewer ailments than those without.

People with outdoor jobs in natural settings—park rangers and park maintenance staff—had it best of all. They said their jobs were less demanding, lower pressure, less frustrating, and so on. It’s possible that such jobs are actually less demanding and lower pressure, but given how nature affects office workers, I wouldn’t be surprised if being immersed in nature plays an important role.

Alas, as a writer I don’t have many excuses to work outside. But I shouldn’t complain too much. My three trees are certainly better than Peter’s view before his renovations and far better than many people who work in windowless caverns.

Photo by Jeremy Levine Design.


Kaplan, R. (1993). The role of nature in the context of the workplace Landscape and Urban Planning, 26 (1-4), 193-201 DOI: 10.1016/0169-2046(93)90016-7

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For metros, two cities can be better than one

Map of photos taken in Minneapolis and St. Paul, Minnesota

Cities were, for thousands of years, distinct and easily identifiable entities. You were either in the city or in the country. Medieval cities took this to the extreme, building walls to make explicit the distinction. Johann Heinrich von Thünen systematized the idea in 1826 when he sketched a hypothetical map that, when simplified, looked like a bow-and-arrow target. The city sat in the center and was surrounded by rings of successively less valuable farmland. It was all very orderly and very German. And for a while it did a good job describing the relationship between the city and the hinterland.

Then came the railroads and automobiles that shot holes through von Thünen’s well-organized bullseye. And in places where two cities were less than a few dozen miles apart, even the boundary between the two became blurred. Today, it’s not uncommon to find metropolitan areas with two, three, even four major cities anchoring them.

Von Thunen's model of land use

Multi-city metros would seem to be a many-headed monster, riddled with contrary opinions and paralyzed by indecision. But that doesn’t alway seem to be the case. As far as labor productivity is concerned, multi-city metros—or polycentric metros, as the literature calls them—may have a distinct advantage. A study of all metropolitan areas in the United States with populations above 250,000 by Evert Meijers and Martijn Burger shows that productivity is higher in metros with more than one city. The effect is especially pronounced among smaller metro areas.

Meijers and Burger speculate that’s because smaller cities tend to have smaller problems—less traffic, lower crime rates, and so on. By splitting the problems up among a few cities, polycentric metros can host a large population without experiencing the problems of a similarly sized, monocentric metro.

But the advantages of multi-city metros diminish as the entire area’s population grows. It’s as though the larger entity needs one place to focus its efforts. So a metro area with two cities, each one-half the size of London, wouldn’t necessarily be more productive than London itself.

Multi-city metros also fall short on other critical parts of city life—cultural and leisure opportunities. Cultural outposts like opera houses and art museums benefit greatly from larger populations, which typically contain more benefactors, both wealthy and otherwise. The same goes for sports teams. Every city would like one for themselves. Say Ft. Worth wants to build an art museum. It’s probably not going to attract some donors from Dallas, who would rather see one built in their city. Chicago doesn’t have such a problem. Monocentric metros don’t have to worry about sharing.

As cities’ borders swell, multi-city urban agglomerations are probably going to be more and more common. Even within existing metropolitan areas, smaller cities could rise to prominence. Minneapolis and St. Paul, for example, have had to contend with the rise of Bloomington. The key will be for leaders to learn to work together, coordinating efforts rather than stepping on each other’s toes.


Meijers, E. (2008). Summing Small Cities Does Not Make a Large City: Polycentric Urban Regions and the Provision of Cultural, Leisure and Sports Amenities Urban Studies, 45 (11), 2323-2342 DOI: 10.1177/0042098008095870

Meijers, E., & Burger, M. (2010). Spatial structure and productivity in US metropolitan areas Environment and Planning A, 42 (6), 1383-1402 DOI: 10.1068/a42151

Map of the Twin Cities by the inimitable Eric Fischer.

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Population density and the evolution of ownership

Lamborghini Aventador in traffic

Yours. Mine. Even a two year-old can understand the basics of ownership. Those two words are also freighted with meaning, implying volumes about resources, control, privilege, and social standing. But what they don’t say is why it is we care so much about who owns what.

There are a number of possible reasons for why we value our possessions and covet those of others. True to form, I found one paper that suggests that population density may be responsible for the evolution of ownership. It’s a game theoretic study by Japanese behavioral scientist Shiro Horiuchi in which he uses an established mathematical model—the Hawk-Dove-Bourgeois game—to sift through the possible origins of possession in both animals and humans.

The Hawk-Dove-Bourgeois game (HDB) is a modification of the classic Hawk-Dove game. In addition to the two existing player types—hawks, who fight to acquire resources or territory and viciously defend what’s theirs, and doves, who avoid conflict at all costs—HDB adds a third strategy, called bourgeois. Bourgeois are a bit of a hybrid of the two existing approaches. A bourgeois player, when challenged for ownership, will fight furiously to keep it. But unlike hawks, they won’t attack other players to acquire resources.

Horiuchi took this game and threw out the standard dove and bourgeois strategies, replacing them instead with strong and weak bourgeois. Weak bourgeois are more similar to doves, which means they are less likely to engage in conflicts. Strong bourgeois can adopt a hawk- or dove-like stance depending on their territorial boundaries: If the contested area is within their boundaries, they’ll fight like hawks. If not, they’ll sit out like doves. Players can change strategies depending on how well they are doing relative to their neighbors. The goal is to control 10 units of territory.

In layman’s terms, the strong bourgeois strategy is a proxy for ownership in its purest sense—strong bourgeois players only fight to retain what’s theirs; anything else and they abstain from conflict. And what emerged from the games was a clear picture of strong bourgeois dominance at higher population densities. That doesn’t mean strong bourgeois players controlled more territory—remember, they were limited to a maximum of 10 units. Rather it means that more players adopted that strategy, judging that it was the best way to obtain and hold the maximum territory, especially as the playing field became more crowded.

Previous studies that used the unmodified HDB game didn’t come to the same conclusion, arguing that the bourgeois strategy—ownership, in other words—isn’t advantageous when resources are high. But those findings are refuted by real world studies of primates that show groups are willing to defend resource-rich home ranges, Horiuchi points out. His modifications and results more closely match the empirical data and suggest that ownership not only arises as population densities increase, but that it’s the best way to succeed.

As an ecologist, this result did not surprise me. In ecology, resources are everything. Even organisms as sedate as plants compete ferociously for resources, employing competitive tactics that range from rapid growth to chemical warfare. But in modern, developed societies where the bare necessities are frequently met, I wondered how these findings might apply. I ran Horiuchi’s result past a friend of mine who is a social psychologist, and he indicated that ownership today is not merely about resources, but status. Controlling more territory—or even just expressing one’s wealth in ever more ostentatious ways through possessions—is just another way in which the strong bourgeois strategy could continue to exert its influence, even though we’re not struggling to survive.

Frankly, I’m not surprised. Based on anecdotal observations of the various places I’ve lived, possessions appear to play a larger role in people’s lives the denser and more populous a city becomes. In large cities, people who earn double their peers seem more inclined to flaunt that wealth compared with the same individuals in smaller towns. The social psychological explanation makes sense in this case. It’s harder to stand out in denser, more populous places, which may lead to more conspicuous consumption.


Horiuchi, S. (2007). High population density promotes the evolution of ownership Ecological Research, 23 (3), 551-556 DOI: 10.1007/s11284-007-0408-6

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