This [EuroNews article](https://www.euronews.com/2020/02/23/berlin-starts-controversial-rent-freeze-on-1-5-million-homes) tells us about the Berlin freezing of rent prices:

> 
> Berlin is freezing the rents of 1.5 million apartments for the next
>  five years starting this Sunday in a controversial move to control the
>  exploding costs that have forced many to move outside Germany's
>  capital city.
> 
> 
> 

This seems to be a rather strange decision in a free market. While the article does not specify the underlying cause of the rising prices, I expect to be related to:

* more and more high-income people come to work in Berlin
* new residential building are too few compared to the number of persons who want to live in Berlin

Clearly capping the rent prices does not seem to tackle the causes above and I am wondering what the authorities hope to achieve with this.

**Question:** Why did Berlin freeze the rent prices as opposed to letting the market set the price?