Is There Really an Upside to Manhattan's Unaffordability?

Bill Keller has a column in the Sunday New York Times assessing Mayor Michael Bloomberg's legacy, mostly with approval. The former media mogul, Keller argues, has proven that CEOs can make good public stewards. City government, he suggests, has never been run as well, by quite so many competent (if not terribly diverse) data wonks. Under Bloomberg, the city weathered the recession, embraced alternative transportation, and expanded its parks and its ambition.

Undoubtedly, a lot of people will spend the next several months (and longer) parsing the legacy of the man who believed he was so uniquely qualified for this job that he had the city's term limits amended so that he could run for a third time. And on some points (Bloomberg's support of stop-and-frisk), there will be much more disagreement than others (his smoking ban, now widely embraced). But one argument in particular from Keller's column certainly deserves a wider airing, in New York City and any city where it feels like even the middle class has been priced out to the perimeter: