Social sciences cannot very well prove things by experiment, but one statistics you can look at is the price difference of apartment sales depending on whether

Social sciences cannot very well prove things by experiment, but one statistics you can look at is the price difference of apartment sales depending on whether it is vacant, or occupied by a tenant. In a normal housing market there is not much difference. A bad tenant is a risk but a good tenant coming with the apartment is an asset. In Paris, the price difference is significant, with sales prices around 10 % lower for an apartment which has a tenant, depending on area and type of apartment. This shows that tenants are seen primarily as a risk and the housing market is off balance. This also means that an apartment owner does not wish to take the risk of leasing out in the short term, and the regulation actually increases rental housing shortage.