Matt Yglesias buys my argument that the phenomenon of empty storefronts is a function of long commercial leases, “but only to an extent”:

If you look at suburban strip malls, the same long lease dynamic applies, but widespread strip mall vacancies are normally a sign of specific economic distress. The current recession has less to a lot of them, but in normal economic times you tend not to see this. Instead, even depressed areas reach a low-rent equilibrium. Possibly this is because strip mall property is less speculative in nature than urban property. But I think the specifically urban nature of the problem probably has something to do with the level of regulatory uncertainty surrounding new retail endeavors in most American cities combined with the reluctance of many neighborhoods to play host to the sort of “uncool” national retail chains that could better manage the risks involved.