"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."It has been a while since I read Death and Life, but I was fairly certain Jacobs had not made such an argument. A search of my copy of her book, specifically the chapter titled "The Need For Aged Buildings," yielded the following quote:
"A successful city becomes a kind of ever-normal granary so far as construction is concerned. Some of the old buildings, year by year, are replaced by new ones -- or rehabilitated to a degree equivalent to replacement. Over the years there is, therefore, constantly a mixture of buildings of many ages and types. This is, of course, a dynamic process, with what was once new in the mixture eventually becoming old in the mixture. ... Time makes the high building costs of one generation the bargains of the following generation." The Death and Life of Great American Cities, pp. 246-47.So Jacobs was not arguing against replacing old buildings per se, but simply against replacing them all at the same time, a position that served as a critique of the prevailing urban renewal methods of her day.
Her point flowed from the common sense economic observation that "a depreciated building requires less income than one that has not paid off its capital costs;" (p. 248); and therefore is likely to charge less in rent than the newly-constructed building. It is this variety in costs and types of buildings, Jacobs argued, that enables a diversity of uses within a city neighborhood.
Nor was Jacobs opposed to tall buildings and high densities, so long as density was not so great so as to result in standardization that would reduce or eliminate a diversity of uses (p. 277). These points are made repeatedly and with great clarity in the book, so it is disappointing that Glaeser would represent them inaccurately. Meanwhile, other legitimate arguments in favor of height limits, including non-economic ones, go unmentioned in the piece. These deserve their own separate treatment in a new post.