part of the "problem" is that rent contracts are unlimited, so if rents are to low, then it may make sense to wait until they rise before renting out, especially in sight of a law that doesn't allow any raises for the time being. but as the article points out, many instead opted to sell outright.
So, to your point, this law of capping rents would then incentivize landlords to keep rental units vacant? Wow, sounds like exactly the kind of effect one can expect from laws suggested by Red-Red-Green in Berlin that lack any common sense or basic understanding of markets.
the very article you posted earlier shows that when the price controls were applied, a significant amount of rental properties were instead offered for sale. my interpretation is that these sellers didn't think that renting out at those prices was worth it, or soon wouldn't be.
i highly doubt that these people, when confronted with a more competitive market would choose to lower rent to compete instead of again just sell.
so i highly doubt that more rental units will automatically lead to lower rents.
“ so i highly doubt that more rental units will automatically lead to lower rents.”
They will IF landlords can expect positive returns on their investments given a certain price level. You can dig into the public filings of companies like LEG, Vonovia and TAG who publish the average rental prices and the occupancy. In cities with supply exceeding demand, rents are lower (e.g., high vacancy rates). Example: https://irpages2.eqs.com/download/companies/legimmobilien/Qu..., page 5.
There is of course also a big callout with respect to “correlation does not imply causation”, e.g., it is very likely that there is a hidden confounder (economic prosperity) that drives down vacancy rates and drives up rents which ties back to my earlier argument that capping rents doesn’t make sense if the cities, politicians and bureaucrats fail miserably at their jobs.
Maybe get a business degree or learn something about it. Your statements make me cringe very much the same way an MBA explaining LLMs to you may make you very miserable.
In Narnia? Go look at the actual vacancy rate.