How Skyscrapers Can Save the City


In the book of Genesis, the builders of Babel declared, “Come, let us build us a city and a tower with its top in the heavens. And let us make a name for ourselves, lest we be scattered upon the face of the whole earth.” These early developers correctly understood that cities could connect humanity. But God punished them for monumentalizing terrestrial, rather than celestial, glory. For more than 2,000 years, Western city builders took this story’s warning to heart, and the tallest structures they erected were typically church spires. In the late Middle Ages, the wool-making center of Bruges became one of the first places where a secular structure, a 354-foot belfry built to celebrate cloth-making, towered over nearby churches. But elsewhere another four or five centuries passed before secular structures surpassed religious ones. With its 281-foot spire, Trinity Church was the tallest building in New York City until 1890. Perhaps that year, when Trinity’s spire was eclipsed by a skyscraper built to house Joseph Pulitzer’s New York World, should be seen as the true start of the irreligious 20th century. At almost the same time, Paris celebrated its growing wealth by erecting the 1,000-foot Eiffel Tower, which was 700 feet taller than the Cathedral of Notre-Dame.

Also see:

Interactive Graphic: How High Can We Go?

The ceaseless climb of the world's skyscrapers is a story of ever-evolving challenges. Here's how we reached the heights we have—and where we might go from here.

Since that tower in Babel, height has been seen both as a symbol of power and as a way to provide more space on a fixed amount of land. The belfry of Trinity Church and Gustave Eiffel’s tower did not provide usable space. They were massive monuments to God and to French engineering, respectively. Pulitzer’s World Building was certainly a monument to Pulitzer, but it was also a relatively practical means of getting his growing news operation into a single building.

For centuries, ever taller buildings have made it possible to cram more and more people onto an acre of land. Yet until the 19th century, the move upward was a moderate evolution, in which two-story buildings were gradually replaced by four- and six-story buildings. Until the 19th century, heights were restricted by the cost of building and the limits on our desire to climb stairs. Church spires and belfry towers could pierce the heavens, but only because they were narrow and few people other than the occasional bell-ringer had to climb them. Tall buildings became possible in the 19th century, when American innovators solved the twin problems of safely moving people up and down and creating tall buildings without enormously thick lower walls.

Elisha Otis didn’t invent the elevator; Archimedes is believed to have built one 2,200 years ago. And Louis XV is said to have had a personal lift installed in Versailles so that he could visit his mistress. But before the elevator could become mass transit, it needed a good source of power, and it needed to be safe. Matthew Boulton and James Watt provided the early steam engines used to power industrial elevators, which were either pulled up by ropes or pushed up hydraulically. As engines improved, so did the speed and power of elevators that could haul coal out of mines or grain from boats.

But humans were still wary of traveling long distances upward in a machine that could easily break and send them hurtling downward. Otis, tinkering in a sawmill in Yonkers, took the danger out of vertical transit. He invented a safety brake and presented it in 1854 at New York’s Crystal Palace Exposition. He had himself hoisted on a platform, and then, dramatically, an axman severed the suspending rope. The platform dropped slightly, then came to a halt as the safety brake engaged.

The Otis elevator became a sensation. In the 1870s, it enabled pathbreaking structures, like Richard Morris Hunt’s Tribune Building in New York, to reach 10 stories. Across the Atlantic, London’s 269-foot St. Pancras Station was taller even than the Tribune Building. But the fortress-like appearance of St. Pancras hints at the building’s core problem. It lacks the critical cost-reducing ingredient of the modern skyscraper: a load-bearing steel skeleton. Traditional buildings, like St. Pancras or the Tribune Building, needed extremely strong lower walls to support their weight. The higher a building went, the thicker its lower walls had to be, and that made costs almost prohibitive, unless you were building a really narrow spire.

The load-bearing steel skeleton, which pretty much defines a skyscraper, applies the same engineering principles used in balloon-frame houses, which reduced the costs of building throughout rural 19th-century America. A balloon-frame house uses a light skeleton made of standardized boards to support its weight. The walls are essentially hung on the frame like a curtain. Skyscrapers also rest their weight on a skeleton frame, but in this case the frame is made of steel, which became increasingly affordable in the late 19th century.

There is a lively architectural debate about who invented the skyscraper—reflecting the fact that the skyscraper, like most other gifts of the city, didn’t occur in a social vacuum, and did not occur all at once. William Le Baron Jenney’s 138-foot Home Insurance Building, built in Chicago in 1885, is often seen as the first true skyscraper. But Jenney’s skyscraper didn’t have a complete steel skeleton. It just had two iron-reinforced walls. Other tall buildings in Chicago, such as the Montauk Building, designed by Daniel Burnham and John Root and built two years earlier, had already used steel reinforcement. Industrial structures, like the McCullough Shot and Lead Tower in New York and the St. Ouen dock warehouse near Paris, had used iron frames decades before.

Jenney’s proto-skyscraper was a patchwork, stitching together his own innovations with ideas that were in the air in Chicago, a city rich with architects. Other builders, like Burnham and Root, their engineer George Fuller, and Louis Sullivan, a former Jenney apprentice, then further developed the idea. Sullivan’s great breakthrough came in 1891, when he put up the Wainwright Building in St. Louis, a skyscraper free from excessive ornamental masonry. Whereas Jenney’s buildings evoke the Victorian era, the Wainwright Building points the way toward the modernist towers that now define so many urban skylines.

Ayn Rand’s novel The Fountainhead is believed to be loosely based on the early life of Sullivan’s apprentice Frank Lloyd Wright. Sullivan and Wright are depicted as lone eagles, Gary Cooper heroes, paragons of individualism. They weren’t. They were great architects deeply enmeshed in an urban chain of innovation. Wright riffed on Sullivan’s idea of form following function, Sullivan riffed on Jenney, and they all borrowed the wisdom of Peter B. Wight, who produced great innovations in fireproofing. Their collective creation—the skyscraper—enabled cities to add vast amounts of floor space using the same amount of ground area. Given the rising demand for center-city real estate, the skyscraper seemed like a godsend. The problem was that those city centers already had buildings on them. Except in places like Chicago, where fire had created a tabula rasa, cities needed to tear down to build up.

The demand for space was even stronger in New York than in Chicago, and skyscrapers were soon springing up in Manhattan. In 1890, Pulitzer’s World Building had some steel framing, but its weight was still supported by seven-foot-thick masonry walls. In 1899, the Park Row Building soared over the World Building, to 391 feet, supported by a steel skeleton. Daniel Burnham traveled east to build his iconic Flatiron Building in 1902, and several years later, Wight’s National Academy of Design was torn down to make way for the 700-foot Metropolitan Life tower, then the tallest building in the world. In 1913, the Woolworth Building reached 792 feet, and it remained the world’s tallest until the boom of the late ’20s.

Those tall buildings were not mere monuments. They enabled New York to grow and industries to expand. They gave factory owners and workers space that was both more humane and more efficient. Manhattan’s master builders, such as A. E. Lefcourt, made that possible.

Like a proper Horatio Alger figure, Lefcourt was born poor and started work as a newsboy and bootblack. By his teenage years, he had saved enough cash to buy a $1,000 U.S. Treasury bond, which he kept pinned inside his shirt. At 25, Lefcourt took over his employer’s wholesale business, and over the next decade he became a leading figure in the garment industry.

In 1910, Lefcourt began a new career as a real-estate developer, putting all of his capital into a 12-story loft building on West 25th Street for his own company. He built more such buildings, and helped move his industry from the old sweatshops into the modern Garment District. The advantage of the garment industry’s old home downtown had been its proximity to the port. Lefcourt’s new Garment District lay between Grand Central and Pennsylvania stations, anchored by the rail lines that continued to give New York a transportation advantage. Transportation technologies shape cities, and Midtown Manhattan was built around two great rail stations that could carry in legions of people.

Also see:

City Limits: A Conversation With Edward Glaeser

The author comments on preserving Paris, the hazards of housing projects, and why measures aimed at saving our cities may actually threaten their survival.

Over the next 20 years, Lefcourt would erect more than 30 edifices, many of them skyscrapers. He used those Otis elevators in soaring towers that covered 150 acres, encased 100 million cubic feet, and contained as many workers as Trenton. “He demolished more historical landmarks in New York City than any other man had dared to contemplate,” TheWall Street Journal wrote. In the early 1920s, the New York of slums, tenements, and Gilded Age mansions was transformed into a city of skyscrapers, as builders like Lefcourt erected nearly 100,000 new housing units each year, enabling the city to grow and to stay reasonably affordable.

By 1928, Lefcourt’s real-estate wealth had made him a billionaire in today’s dollars. He celebrated by opening a national bank bearing his own name. Lefcourt’s optimism was undiminished by the stock-market crash, and he planned $50 million of construction for 1930, sure that it would be a “great building year.” But as New York’s economy collapsed, so did his real-estate empire, which was sold off piecemeal to pay his investors. He died in 1932 worth only $2,500, seemingly punished, like the builders of Babel, for his hubris.

I suspect that Lefcourt, like many developers, cared more about his structural legacy than about cash. Those structures helped house the creative minds that still make New York special. His most famous building, which doesn’t even bear his name, came to symbolize an entire musical style: the “Brill Building Sound.” In the late 1950s and early ’60s, artists connected in the Brill Building, producing a string of hits like “Twist and Shout,” “You’ve Lost That Lovin’ Feelin’,” and, fittingly enough, “Up on the Roof.” Cities are ultimately about the connections between people, and structures—like those built by Lefcourt—make those connections possible. By building up, Lefcourt made the lives of garment workers far more pleasant and created new spaces for creative minds.

New York’s upward trajectory was not without its detractors. In 1913, the distinguished chairman of the Fifth Avenue Commission, who was himself an architect, led a fight to “save Fifth Avenue from ruin.” At that time, Fifth Avenue was still a street of stately mansions owned by Carnegies and Rockefellers. The anti-growth activists argued that unless heights were restricted to 125 feet or less, Fifth Avenue would become a canyon, with ruinous results for property values and the city as a whole. Similar arguments have been made by the enemies of change throughout history. The chair of the commission was a better architect than prognosticator, as density has suited Fifth Avenue quite nicely.

Also see:

Gallery: The Architecture of Louis Sullivan

Historic photographs of some of Louis Sullivan's most renowned and intriguing buildings.

The Atlantic on Skyscrapers and Cities
Writings by Robert Moses, Richard Florida, Witold Rybczynski, Philip Langdon, and others, from the Atlantic's archives.

In 1915, between Broadway and Nassau Street, in the heart of downtown New York, the Equitable Life Assurance Society constructed a monolith that contained well over a million square feet of office space and, at about 540 feet, cast a seven-acre shadow on the city. The building became a rallying cry for the enemies of height, who wanted to see a little more sun. A political alliance came together and passed the city’s landmark 1916 zoning ordinance, which allowed buildings to rise only if they gave up girth. New York’s many ziggurat-like structures, which get narrower as they get taller, were constructed to fulfill the setback requirements of that ordinance.

The code changed the shape of buildings, but it did little to stop the construction boom of the 1920s. Really tall buildings provide something of an index of irrational exuberance. Five of the 10 tallest buildings standing in New York City in 2009—including the Empire State Building—were completed between 1930 and ’33. In the go-go years of the late ’20s, when the city’s potential seemed unlimited, builders like Lefcourt were confident they could attract tenants, and their bankers were happy to lend. The builders of the Chrysler Building, 40 Wall Street, and the Empire State Building engaged in a great race to produce the tallest structure in the world. It is an odd fact that two of New York’s tallest and most iconic edifices were built with money made from selling the cars that would move America away from vertical cities to sprawling suburbs. As it turned out, the winner, the Empire State Building, was soon nicknamed the “Empty State Building”—it was neither fully occupied nor profitable until the 1940s. Luckily for its financiers, the building’s construction had come in way below budget.

New York slowed its construction of skyscrapers after 1933, and its regulations became ever more complex. Between 1916 and 1960, the city’s original zoning code was amended more than 2,500 times. In 1961, the City Planning Commission passed a new zoning resolution that significantly increased the limits on building. The resulting 420-page code replaced a simple classification of space—business, residential, unrestricted—with a dizzying number of different districts, each of which permitted only a narrow range of activities. There were 13 types of residential district, 12 types of manufacturing district, and no fewer than 41 types of commercial district.

Each type of district narrowly classified the range of permissible activities. Commercial art galleries were forbidden in residential districts but allowed in manufacturing districts, while noncommercial art galleries were forbidden in manufacturing districts but allowed in residential districts. Art-supply stores were forbidden in residential districts and some commercial districts. Parking-space requirements also differed by district. In an R5 district, a hospital was required to have one off-street parking spot for every five beds, but in an R6 district, a hospital had to have one space for every eight beds. The picayune detail of the code is exemplified by its control of signs:

For multiple dwellings, including apartment hotels, or for permitted non-residential buildings or other structures, one identification sign, with an area not exceeding 12 square feet and indicating only the name of the permitted use, the name or address of the building, or the name of the management thereof, is permitted.

The code also removed the system of setbacks and replaced it with a complex system based on the floor-to-area ratio, or FAR, which is the ratio of interior square footage to ground area. A maximum FAR of two, for example, meant that a developer could put a two-story building on his entire plot or a four-story building on half of the plot. In residential districts R1, R2, and R3, the maximum floor-to-area ratio was 0.5. In R9 districts, the maximum FAR was about 7.5, depending on the building height. The height restriction was eased for builders who created plazas or other public spaces at the front of the building. While the standard building created by the 1916 code was a wedding cake that started at the sidewalk, the standard building created by the 1961 code was a glass-and-steel slab with an open plaza in front.

New York’s zoning codes were getting more rigorous, but so were other restrictions on development. After World War II, New York made private development more difficult by overregulating construction and rents, while building a bevy of immense public structures, such as Stuyvesant Town and Lincoln Center.

But then, during the 1950s and ’60s, both public and private projects ran into growing resistance from grassroots organizers like Jane Jacobs, who were becoming adept at mounting opposition to large-scale development. In 1961, Jacobs published her masterpiece, The Death and Life of Great American Cities, which investigates and celebrates the pedestrian world of mid-20th-century New York. She argued that mixed-use zoning fostered street life, the essence of city living. But Jacobs liked protecting old buildings because of a confused piece of economic reasoning. She thought that preserving older, shorter structures would somehow keep prices affordable for budding entrepreneurs. That’s not how supply and demand works. Protecting an older one-story building instead of replacing it with a 40-story building does not preserve affordability. Indeed, opposing new building is the surest way to make a popular area unaffordable. An increase in the supply of houses, or anything else, almost always drives prices down, while restricting the supply of real estate keeps prices high.

The relationship between housing supply and affordability isn’t just a matter of economic theory. A great deal of evidence links the supply of space with the cost of real estate. Simply put, the places that are expensive don’t build a lot, and the places that build a lot aren’t expensive. Perhaps a new 40-story building won’t itself house any quirky, less profitable firms, but by providing new space, the building will ease pressure on the rest of the city. Price increases in gentrifying older areas will be muted because of new construction. Growth, not height restrictions and a fixed building stock, keeps space affordable and ensures that poorer people and less profitable firms can stay and help a thriving city remain successful and diverse. Height restrictions do increase light, and preservation does protect history, but we shouldn’t pretend that these benefits come without a cost.

In 1962, in response to the outcry over the razing of the original Pennsylvania Station, which was beautiful and much beloved, Mayor Robert Wagner established the Landmarks Preservation Commission. In 1965, despite vigorous opposition from the real-estate industry, the commission became permanent. Initially, this seemed like a small sop to preservationists. The number of buildings landmarked in the commission’s first year, 1,634, was modest, and the commission’s power was checked by the city council, which could veto its decisions.

Yet, like entropy, the reach of governmental agencies often expands over time, so that a mild, almost symbolic group can come to influence vast swaths of a city. By 2008, more than 15 percent of Manhattan’s non-park land south of 96th Street was in a historic district, where every external change must be approved by the commission. By the end of 2010, the commission had jurisdiction over 27,000 landmarked buildings and 101 historic districts.

In 2006, the developer Aby Rosen proposed putting a glass tower of more than 20 stories atop the old Sotheby Parke-Bernet building at 980 Madison Avenue, in the Upper East Side Historic District. Rosen and his Pritzker Prize–winning architect, Lord Norman Foster, wanted to erect the tower above the original building, much as the MetLife Building (formerly the Pan Am Building) rises above Grand Central Terminal. The building was not itself landmarked, but well-connected neighbors didn’t like the idea of more height, and they complained to the commission. Tom Wolfe, who has written brilliantly about the caprices of both New York City and the real-estate industry, wrote a 3,500-word op-ed in The New York Times warning the landmarks commission against approving the project. Wolfe & Company won. In response to his critics in the 980 Madison Avenue case, of whom I was one, Wolfe was quoted in The Village Voice as saying:

To take [Glaeser’s] theory to its logical conclusion would be to develop Central Park … When you consider the thousands and thousands of people who could be housed in Central Park if they would only allow them to build it up, boy, the problem is on the way to being solved!

But one of the advantages of building up in already dense neighborhoods is that you don’t have to build in green areas, whether in Central Park or somewhere far from an urban center. From the preservationist perspective, building up in one area reduces the pressure to take down other, older buildings. One could quite plausibly argue that if members of the landmarks commission have decided that a building can be razed, then they should demand that its replacement be as tall as possible.

The cost of restricting development is that protected areas have become more expensive and more exclusive. In 2000, people who lived in historic districts in Manhattan were on average almost 74 percent wealthier than people who lived outside such areas. Almost three-quarters of the adults living in historic districts had college degrees, as opposed to 54 percent outside them. People living in historic districts were 20 percent more likely to be white. The well-heeled historic-district denizens who persuade the landmarks commission to prohibit taller structures have become the urban equivalent of those restrictive suburbanites who want to mandate five-acre lot sizes to keep out the riffraff. It’s not that poorer people could ever afford 980 Madison Avenue, but restricting new supply anywhere makes it more difficult for the city to accommodate demand, and that pushes up prices everywhere.

Again, the basic economics of housing prices are pretty simple—supply and demand. New York and Mumbai and London all face increasing demand for their housing, but how that demand affects prices depends on supply. Building enough homes eases the impact of rising demand and makes cities more affordable. That’s the lesson of both Houston today and New York in the 1920s. In the post-war boom years between 1955 and 1964, Manhattan issued permits for an average of more than 11,000 new housing units each year. Between 1980 and ’99, when the city’s prices were soaring, Manhattan approved an average of 3,100 new units per year. Fewer new homes meant higher prices; between 1970 and 2000, the median price of a Manhattan housing unit increased by 284 percent in constant dollars.

The other key factor in housing economics is the cost of building a home. The cheapest way to deliver new housing is in the form of mass-produced two-story homes, which typically cost only about $84 a square foot to erect. That low cost explains why Atlanta and Dallas and Houston are able to supply so much new housing at low prices, and why so many Americans have ended up buying affordable homes in those places.

Building up is more costly, especially when elevators start getting involved. And erecting a skyscraper in New York City involves additional costs (site preparation, legal fees, a fancy architect) that can push the price even higher. But many of these are fixed costs that don’t increase with the height of the building. In fact, once you’ve reached the seventh floor or so, building up has its own economic logic, since those fixed costs can be spread over more apartments. Just as the cost of a big factory can be covered by a sufficiently large production run, the cost of site preparation and a hotshot architect can be covered by building up. The actual marginal cost of adding an extra square foot of living space at the top of a skyscraper in New York is typically less than $400. Prices do rise substantially in ultra-tall buildings—say, over 50 stories—but for ordinary skyscrapers, it doesn’t cost more than $500,000 to put up a nice 1,200-square-foot apartment. The land costs something, but in a 40-story building with one 1,200-square-foot unit per floor, each unit is using only 30 square feet of Manhattan—less than a thousandth of an acre. At those heights, the land costs become pretty small. If there were no restrictions on new construction, then prices would eventually come down to somewhere near construction costs, about $500,000 for a new apartment. That’s a lot more than the $210,000 that it costs to put up a 2,500-square-foot house in Houston—but a lot less than the $1 million or more that such an apartment often costs in Manhattan.

Land is also pretty limited in Chicago’s Gold Coast, on the shores of Lake Michigan. Demand may not be the same as in Manhattan, but it’s still pretty high. Yet you can buy a beautiful condominium with a lake view for roughly half the cost of a similar unit in Manhattan. Building in Chicago is cheaper than in New York—but it’s not twice as cheap. The big cost difference is that Chicago’s leadership has always encouraged new construction more than New York’s (at least before the Bloomberg administration). The forest of cranes along Lake Michigan keeps Chicago affordable.

Most people who fight to stop a new development think of themselves as heroes, not villains. After all, a plan to put up a new building on Madison Avenue clearly bugs a lot of people, and preventing one building isn’t going to make much difference to the city as a whole. The problem is that all those independent decisions to prohibit construction add up. Zoning rules, air rights, height restrictions, and landmarks boards together form a web of regulation that has made building more and more difficult. The increasing wave of regulations was, until the Bloomberg administration, making New York shorter. In a sample of condominium buildings, I found that more than 80 percent of Manhattan’s residential buildings built in the 1970s had more than 20 stories. But less than 40 percent of the buildings put up in the 1990s were that tall. The elevator and the steel-framed skyscraper made it possible to get vast amounts of living space onto tiny amounts of land, but New York’s building rules were limiting that potential.

The growth in housing supply determines not only prices but the number of people in a city. The statistical relationship between new building and population growth within a given area is almost perfect, so that when an area increases its housing stock by 1 percent, its population rises by almost exactly that proportion. As a result, when New York or Boston or Paris restricts construction, its population will be smaller. If the restrictions become strong enough, then a city can even lose population, despite rising demand, as wealthier, smaller families replace poorer, larger ones.

Jane Jacobs’s insights into the pleasures and strengths of older, shorter urban neighborhoods were certainly correct, but she had too little faith in the strengths of even-higher density levels. I was born a year before Jacobs left New York for Toronto, and I lived in Manhattan for the next 17 years. Yet my neighborhood looked nothing like low-rise Greenwich Village. I grew up surrounded by white glazed towers built after World War II to provide affordable housing for middle-income people like my parents. The neighborhood may not have been as charming as Greenwich Village, but it had plenty of fun restaurants, quirky stores, and even-quirkier pedestrians. The streets were reasonably safe. It was certainly a functioning, vibrant urban space, albeit one with plenty of skyscrapers.



















The success of our cities, the world’s economic engines, increasingly depends on abstruse decisions made by zoning boards and preservation committees. It certainly makes sense to control construction in dense urban spaces, but I would replace the maze of regulations now limiting new construction with three simple rules.

Also see:

The 30 Most Dynamic Cities in the World

Grading each metropolis by the growth of its income and employment, a new study found the world's fastest recovering cities are overwhelmingly in three key areas: China and India, Southeast Asian islands, and Latin America

The 20 Cities Leading the U.S. Recovery
Areas that traded the boom-and-bust real estate business for Meds, Eds, Feds and Enlisteds only got spritzed by the recession while most cities felt the full force of the economic tsunami.

First, cities should replace the lengthy and uncertain permitting processes now in place with a simple system of fees. If tall buildings create costs by blocking out light or views, then form a reasonable estimate of those costs and charge the builder appropriately. The money from those fees could then be given to the people who are suffering, such as the neighbors who lose light from a new construction project.

I don’t mean to suggest that such a system would be easy to design. There is plenty of room for debate about the costs associated with buildings of different heights. People would certainly disagree about the size of the neighboring areas that should receive compensation. But reasonable rules could be developed that would then be universally applied; for instance, every new building in New York would pay some amount per square foot in compensation costs, in exchange for a speedy permit. Some share of the money could go to the city treasury, and the rest would go to people within a block of the new edifice.

A simple tax system would be far more transparent and targeted than the current regulatory maze. Today, many builders negotiate our system by hiring expensive lawyers and lobbyists and buying political influence. It would be far better for them to just write a check to the rest of us. Allowing more building doesn’t have to be a windfall for developers; sensible, straightforward regulations can make new development good for the neighborhood and the city.

Second, historic preservation should be limited and well defined. Landmarking a masterpiece like the Flatiron Building or the old Penn Station is sensible. Preserving a post-war glazed-brick building is absurd. But where do you draw the line between those two extremes? My own preference is that, in a city like New York, the Landmarks Preservation Commission should have a fixed number of buildings, perhaps 5,000, that it may protect. The commission can change its chosen architectural gems, but it needs to do so slowly. It shouldn’t be able to change its rules overnight to stop construction in some previously unprotected area. If the commission wants to preserve a whole district, then let it spread its 5,000-building mandate across the area. Perhaps 5,000 buildings are too few; but without some sort of limit, any regulatory agency will constantly try to increase its scope. The problem gets thornier in places like Paris, practically all of which is beloved worldwide. In such cases, the key is to find some sizable area, reasonably close to the city center, that can be used for ultra-dense development. Ideally, this space would be near enough to let its residents enjoy walking to the beautiful streets of the older city.

Finally, individual neighborhoods should have more power to protect their special character. Some blocks might want to exclude bars. Others might want to encourage them. Rather than regulate neighborhoods entirely from the top down, let individual neighborhoods enforce their own, limited rules that are adopted only with the approval of a large share of residents. In this way, ordinary citizens, rather than the planners in City Hall, would get a say over what happens around them.

Great cities are not static—they constantly change, and they take the world along with them. When New York and Chicago and Paris experienced great spurts of creativity and growth, they reshaped themselves to provide new structures that could house new talent and new ideas. Cities can’t force change with new buildings—as the Rust Belt’s experience clearly shows. But if change is already happening, new building can speed the process along.

Yet many of the world’s old and new cities have increasingly arrayed rules that prevent construction that would accommodate higher densities. Sometimes these rules have a good justification, such as preserving truly important works of architecture. Sometimes, they are mindless NIMBYism or a misguided attempt at stopping urban growth. In all cases, restricting construction ties cities to their past and limits the possibilities for their future. If cities can’t build up, then they will build out. If building in a city is frozen, then growth will happen somewhere else.

Land-use regulations may seem like urban arcana. But these rules matter because they shape our structures, and our structures shape our societies—often in unexpected ways. Consider that carbon emissions are significantly lower in big cities than in outlying suburbs, and that, as of 2007, life expectancy in New York City was 1.5 years higher than in the nation as a whole. As America struggles to regain its economic footing, we would do well to remember that dense cities are also far more productive than suburbs, and offer better-paying jobs. Globalization and new technologies seem to have only made urban proximity more valuable—young workers gain many of the skills they need in a competitive global marketplace by watching the people around them. Those tall buildings enable the human interactions that are at the heart of economic innovation, and of progress itself.