Almost as a rule, Glaeser is skeptical of the lack-of-land argument. He has previously noted (with a collaborator, Matthew Kahn) that 95 percent of the United States remains undeveloped and that if every American were given a house on a quarter acre, so that every family of four had a full acre, that distribution would not use up half the land in Texas. Most of Boston's metro area, he concluded, wasn't particularly dense, and even in places where it was, like the centers of Boston and Cambridge, there was ample opportunity to construct higher buildings with more housing units.
So, after sorting through a mountain of data, Glaeser decided that the housing crisis was man-made. The region's zoning regulations — which were enacted by locales in the first half of the 20th century to separate residential land from commercial and industrial land and which generally promoted the orderly growth of suburbs — had become so various and complex in the second half of the 20th century that they were limiting growth. Land-use rules of the 1920's were meant to assure homeowners that their neighbors wouldn't raise hogs in their backyards, throw up a shack on a sliver of land nearby or build a factory next door, but the zoning rules of the 1970's and 1980's were different in nature and effect. Regulations in Glaeser's new hometown of Weston, for instance, made extremely large lot sizes mandatory in some neighborhoods and placed high environmental hurdles (some reasonable, others not, in Glaeser's view) in front of developers. Other towns passed ordinances governing sidewalks, street widths, the shape of lots, septic lines and so on — all with the result, in Glaeser's analysis, of curtailing the supply of housing. The same phenomenon, he says, has inflated prices in metro areas all along the East and West Coasts.
Cities, Glaeser often says, should be thought of as "the absence of physical space between people and firms." This sounds like a poetic definition of urbanism, but it is actually more than that. To Glaeser, the concentration of people and business puts us close enough to share one another's company, culture and ideas. That goes not only for a densely packed place like Manhattan but also for car-based areas like Silicon Valley. As David Cutler points out, almost all of Glaeser's work is about social interaction and space, about seeing cities as places where all kinds of important transactions occur in "the union of everything." It is not a coincidence that one of Glaeser's great heroes is the writer Jane Jacobs, a keen, street-level observer of cities who celebrated the freedom and vitality of urban neighborhoods; he keeps an autographed copy of her book "The Death and Life of Great American Cities" on his bookshelf. In economic jargon, city living creates what Glaeser calls "spillovers." Some urban spillovers are not so good, like the pollution and congestion from so many people and cars. But others are the very essence of civilized life — the decency of community, the spread of ideas, the possibility of sublime inspiration. If there is a common theme to his work, Glaeser says, it is that "people are changed by the people around them." And it is the absence of physical distance, more than anything else, that makes that happen.
This evolution, of course, has coincided with a vast American migration toward regions of sun and sprawl. Glaeser likes to point out the close correlation between a city's average January temperature and its urban growth; he also notes that cars per capita in 1990 is among the best indicators of how well a city has fared over the past 15 years. The more cars, the better — a conclusion that seems perfectly logical to Glaeser. Car-based cities enable residents to buy cheaper, bigger houses. And commuters in car-based cities tend to get to work faster than commuters in cities that rely on public transit. (The average car commute is about 24 minutes; on public transportation, it is around 48 minutes.) While many of his academic peers were looking at, and denigrating, how the majority of Americans have chosen to live, Glaeser (though no fan of the aesthetics of sprawl himself) didn't think an economist should allow taste to affect judgment. "You shouldn't go around thinking that all these people are just jackasses for deciding to drive an automobile," he says.
In any case, Glaeser discovered that there can be more to urban success than cars and palm trees. For a city without warm weather and a car-friendly environment, skills are destiny. That is why New York and Minneapolis, with vast numbers of college graduates, have done so well. "Boston would be just another declining, cold, manufacturing city if it weren't for its preponderance of human capital," Glaeser says. And his studies suggest that the more skilled a city's population, the more skilled it is becoming, as entrepreneurs attract skilled workers who in turn attract entrepreneurs. Americans, as a result, are sorting themselves through education and geography more and more with each passing year.
Glaeser, for his part, says he feels the same about New Orleans as he does about many cities of the Rust Belt. "I believe very strongly that our obligation is to people, not places, and I think we certainly have an obligation — ethical, economic, what have you — to the residents of Detroit," he told me. But he sees no economic or geographic reason to have a large city there anymore, and he views the prospects for any rebound as dim. (Detroit ranks last among cities with more than 500,000 residents in percentage of college graduates.) The city produced the cars that produced the sprawl that helped destroy the city; such tragedy might have been lessened had it produced more universities too. "There are no reasons why it can't, and shouldn't, decline," Glaeser says. "And I would say that for many other cities. There's no reason not to let decline go forward." The greatness of America is dependent in part upon regional evolutions and migrations, he adds. "Places decline and places grow. We shouldn't stand in the way of that."
Glaeser and Gyourko determined that the durable nature of housing itself explains this phenomenon. People can flee, but houses can take a century or more to finally fall to pieces. "These places still exist," Glaeser says of Detroit and St. Louis, "because the housing is permanent. And if you want to understand why they're poor, it's actually also in part because the housing is permanent." For Glaeser, this is the story not only of these two places but also of Buffalo, Baltimore, Cleveland, Philadelphia and Pittsburgh — the powerhouse cities of America in 1950 that consistently and inexorably lost population over the next 50 years. It is not just that there were poor people and the jobs left and the poor people were stuck there. "Thousands of poor come to Detroit each year and live in places that are cheaper than any other place to live in part because they've got durable housing still around," Glaeser says. The net population of Detroit usually decreases each year, in other words, but the city still attracts plenty of people drawn by its extreme affordability. As Gyourko points out, in the year 2000 the median house price in Philadelphia was $59,700; in Detroit, it was $63,600. Those prices are well below the actual construction costs of the homes. "To build them new, it would cost at least $80,000," Gyourko says, "so there's no builder who would build those today. And as long as those houses remain, the people remain."
As Glaeser says: "It's so easy to forget the world that we were living in around 1970, when basically almost all of the value of houses was in the physical infrastructure. That was actually the cost. There was some land, and it was worth something, but it wasn't worth more than 20 percent of the value of the house." Even in New York City, Glaeser says, the price of an apartment back then was essentially the cost of building the next floor. In researching New York City's housing prices, in fact, Glaeser and Gyourko discovered that over the past 30 years, the average height of new residential buildings in Manhattan decreased in size. "That's crazy," he insists, especially in light of how much the demand to live in New York has increased. "You know, if prices in Manhattan are skyrocketing, you should be building more and more at 50 stories, rather than at 30. Not the reverse." So is it his contention that Manhattan could build far more than it has recently? "Oh, for sure," he says. "Technologically? Certainly. No reason why you couldn't."
This is not to suggest that Glaeser wants New York or Boston to become another Houston or Phoenix, where developers build without hindrance and housing, as a result, stays cheap. "I'm pretty sure that Boston and California have gone too far to one extreme," he says. "But I'm not sure that Texas hasn't gone too far to the other extreme." He says he tends to think that officials in the Boston and New York metro areas need to allow for more housing when the market gets tighter again. At the very least, he says, officials should discuss the long-term effects of restricting home building. And there is a bigger point here anyway, he says. Zoning and housing supply ultimately determine not only who lives in a city but also the very nature of these places. Boston, San Francisco and Manhattan are obviously becoming rarefied destinations, mostly for America's elites (Glaeser calls the cities "luxury goods"), with housing floating beyond the reach of the young and the middle class. These cities' economies are in the process of becoming boutique, too, accommodating only the most skilled and privileged. Their desire to limit construction and grow not in buildings and population but in prices has, in effect, begun to shape their destiny. "A healthy city is one that has a healthy mix of demographic groups," Glaeser says. "Shutting out your 25-to-40 year-olds? That feels like a bad strategy for urban innovation."
But economists, like any social scientists, often discover that the leap from conducting research to making policy can be enormously difficult. It can take years, perhaps decades — and that's when it happens at all. Glaeser is fortunate in that he already has the ear of mayors and state legislators who at least took notice of his recent work on regulations in the Boston metro area. Still, he admits it will be difficult to go against the current momentum. "I'm not in any sense trying to suggest that we want a developer's paradise where you can build anything, anywhere," he says. "But I sure as heck think the current situation happened by happenstance, happened by changing the legal norms, which in no sense is guaranteed to yield a socially desirable outcome." Homeowners, he points out, have a strong incentive to stop new development, both because it can be an inconvenience and also because, like any monopolist, stopping supply drives up the price of their own homes. "Lack of affordable housing isn't a problem to homeowners," Glaeser says; that's exactly what they want. "The thing you want most is to make sure that your home is not affordable if you own it. And for that reason, there's absolutely no reason to think that little suburban communities with no businesses that are run essentially by their homeowners will make the right decisions for the state as a whole, for the business in the area, for the country as a whole."
