The complexity lies in the web of incentives that make up regional and local politics. The people most negatively affected have the least clout politically. The

The complexity lies in the web of incentives that make up regional and local politics. The people most negatively affected have the least clout politically. The people with the most political influence have a vested interest in ensuring housing prices don't drop. So as a result, the optimal choice for a politician isn't the optimal choice for the city as a whole. Not to mention policies like rent control that can produce a huge sort term political gain, at the expense of making drastically harder to build more housing in the future.