Bad ideas, if they were ever widely accepted, have a curious way of
sticking around. That's because they give rise to institutions that
have a momentum of their own. We've long known there are better ways to
fix blighted neighborhoods than simply pressing "reset" -- that is,
letting the government tear down old buildings and put up new ones. But
we remain saddled with a system of public housing that keeps looking
for ways of, well, pressing reset.