Triumph of the City by Edward Glaeser: Why Density Matters

Triumph of the City (2011) is the book in which the economist Edward Glaeser, a professor at Harvard, argues that the city is humanity's greatest invention because it makes us richer, smarter, greener, healthier and happier. His central claim is that physical proximity multiplies the exchange of ideas, and that this exchange is the source of economic growth and innovation from classical Athens to Silicon Valley. Against the image of the city as a problem, pollution, poverty, crime, Glaeser presents it as the best hope for solving those very problems, on one condition: that it be allowed to grow and densify.

Agglomeration economics: why proximity makes us richer

The economic thesis rests on agglomeration economics. Skilled people are more productive when they work near other skilled people, because they learn from one another, change jobs easily and find specialised clients and suppliers. Glaeser shows that wages rise with city size even after accounting for education, and that cities that lost their industrial base, such as Detroit, did not fall because they were cities but because they bet for decades on a single industry and on buildings rather than people. His recipe for declining cities is to invest in education, not in stadiums or empty skyscrapers.

The dense city is the green city

The most cited chapter is the environmental one. Glaeser calculates that a Manhattan resident emits far less carbon than one in the suburbs of Houston or Atlanta, because they live in fewer square metres, travel by public transport or on foot and share walls that save heating. Hence his provocative conclusion: whoever wants to protect nature should live far from it, in a dense city, and the policies that prevent building upward in San Francisco or New York push growth toward dispersed, hot places where emissions per person are far higher. Environmentalism that blocks density, he says, is self-defeating.

Urban poverty: cities attract the poor, they do not create them

Glaeser also attends to urban poverty, which he reads against common sense: cities do not create the poor, they attract them, because they offer more opportunities than the countryside or the village they come from. The favelas of Rio or the slums of Mumbai are, in his reading, rungs of social mobility rather than failures, as long as the city offers schools, transport and safety. He criticises instead the policies that subsidise home ownership and suburbia, and the height limits that, as in Mumbai, condemn cities to informal density by banning the formal kind.

Criticisms: inequality, affordability and informality

Criticism of the book has been abundant. It is reproached for an optimism that minimises the inequality agglomeration itself produces, a theme Glaeser treated little and that Richard Florida later acknowledged in The New Urban Crisis. His confidence that building more will solve affordability clashes with evidence that new supply goes to high incomes without public policy. And his reading of informality as a springboard ignores those who remain trapped in it. Even so, his defence of density, public transport and education as urban policy has influenced the movement for more housing in the world's most expensive cities.

The lasting relevance of Triumph of the City lies in its question: why cities, which concentrate problems, are also where they are solved. Glaeser answers that proximity between people is a society's most valuable resource, and that urban policy should devote itself to making it possible, by allowing building, moving people without cars and educating the children of poor neighbourhoods. His critics add the condition he left in the background: that the benefits of agglomeration be shared, because a city that triumphs only for some ends up expelling the rest.