Economists Explain Manhattan's Skyline For the First Time
In The Great Gatsby, F. Scott Fitzgerald famously said that, "The city seen from the Queensboro Bridge is always the city seen for the first time, in its first wild promise of all the mystery and the beauty in the world." There’s nothing else in the world like it, especially because of an unusual feature: its twin peaks are separated by the long stretch of low-rise buildings between Downtown and Midtown Manhattan. Conventional wisdom held that Manhattan’s skyscrapers were clustered in two distinct areas because the bedrock between Downtown and Midtown was too far down below the surface, making it difficult to build on. But that myth has officially been debunked.
Manhattan’s skyline was made possible by two things: Henry Bessemer’s advent of the Bessemer Process in 1858 that allowed for the mass production of steel, and the bedrock that the island rests on. The latter is important because without Manhattan’s unique geological foundation - a rock strata that's more than a billion years old - no skyscrapers could have ever risen on the island. You can’t built skyscrapers in someplace like, say, Long Island, where no bedrock exists and the ground is too soft to support the weight of tall buildings. In short, no bedrock, no skyline.
The problem is that the bedrock isn’t always just beneath the surface, which was thought to influence new construction of skyscrapers, whether they be commercial office towers or luxury apartment buildings. In fact, at certain points in Manhattan the bedrock is so deep that it isn’t found until you dig about 45 meters into the ground. The idea that the depth of the bedrock determined Manhattan’s skyline became codified as common sense when geologist Christopher J. Schubert published The Geology of New York City and Environs in 1968. In that seminal book he noticed a definite correlation between skyscraper location and bedrock depth - the deeper the bedrock, the fewer skyscrapers stood in Manhattan. In order to explain this phenomena, he argued that deeper bedrock made large new construction projects much more difficult, and that line of reasoning has been accepted as true ever since.
Enter Jason Barr, Troy Tassier, and Rossen Trendafilov. In December of last year, those three economists published a study on the correlation of skyscrapers and bedrock depth in Manhattan in The Journal of Economic History. They took 173 random core samples from Battery Park City to Central Park South, and they found that some of the tallest buildings in Manhattan were built on the deepest sections of Manhattan’s bedrock, most notably the New York World Building and Woolworth Building. In fact, they found that the most a deep section of bedrock could add to construction costs is somewhere in the range of 7%, and, moreover, they found that there is no correlation between the depth of bedrock and the likelihood of skyscraper construction.
If bedrock wasn’t a significant factor in determining why Manhattan’s skyline looks the way it does, then why is there a section in Manhattan bereft of skyscrapers? And why is there a cluster in Midtown anyway? Answering that question is far beyond the scope of this article, but it certainly had a lot to do with the fact that areas like Chelsea, the Lower East Side, and Greenwich Village were immigrant neighborhoods; most of Manhattan’s wealthier members lived uptown in the residential districts of the Upper East Side and Upper West Side, so developers moved uptown with them. That’s part of the story, and a small part at that.