I don't think it necessarily was caused by rent control. It's still an extremely inconvenient fact for anybody advancing the hypothesis that rent control imped

I don't think it necessarily was caused by rent control. It's still an extremely inconvenient fact for anybody advancing the hypothesis that rent control impedes housing development. It might very well be that the effect is real but is so weak that it is completely overwhelmed by other factors. It might also be that bringing down property values (which rent control will do) lowers the bar to housing development, spurring more of it.