Post

This study is especially scientifically rigorous because of how they do it. They take advantage of quirks in the law: a 1994 reform brought new rent controls for a set of buildings built in 1979 (or earlier), while exempting those built in 1980 (or later).

That means they can watch what happens to rental supply and price in buildings on the same block, otherwise indistinguishable from each other, but for the fact that some were built slightly earlier and got rent control — almost at random.

In other words, this is not “textbook economics”. Textbook models are great starting points. But what counts as much as careful thinking is careful observation of the world. Rent control might seem promising on paper but it has a bad track record in practice. Makes things worse.