Why do liberal cities enact policies that often making housing unaffordable for the poor and much of the middle class? The cynical explanation is that “limousine liberal” voters only pretend to care about affordable housing for the poor and the middle class, but in reality adopt zoning restrictions to keep home prices up and prevent the riffraff from living near them. Such motives may be present in some cases. But, on most issues, there is little correlation between political views and measures of narrow self-interest. It is therefore likely that most voters in liberal cities do genuinely care about affordable housing and the interests of the poor.
The virus that plagues our body politic is not selfish voting, but ignorant voting. Like their conservative counterparts, most liberal voters don’t think carefully about the possible negative side effects of their preferred policies. Just as most of them do not realize that rent control diminishes the stock of housing, they also may not realize that zoning restrictions diminish it, and thereby increase housing costs.
Conservative voters have their own characteristic patterns of economic ignorance. Both sides tend to ignore or even blatantly misinterpret evidence that cuts against their preferred views – especially if the evidence or the reasoning behind it is counterintuitive. To a considerable extent, the high cost of housing in liberal cities is yet another negative effect of widespread political ignorance.
Well-meaning, but ill-informed voters are not exclusively to blame, of course. In many cases, development restrictions are also favored by influential narrow interest groups, such as developers with strong political connections. If it were easy for newcomers to build new housing and office space, these well-connected insiders would lose much of their competitive edge. Unlike ordinary voters, who tend to be rationally ignorant about public policy, small organized interest groups have strong incentives to pay close attention to policies in which they have a major stake.
As is often the case with perverse regulatory policies, excessive zoning is in part the product of a “baptist-bootlegger” coalition. Well-meaning, but badly misguided Baptists supported Prohibition out of genuine moral concern about the harmful effects of alcohol. Meanwhile, bootleggers backed it because it put money in their pockets. Housing policy in liberal cities is influenced by a similar implicit unholy alliance between well-meaning progressive voters and unscrupulous economic interest groups.