[et-al]

There's too many variables to say that rent control for the entire housing stock is what keeps Berlin's rents down.

For starters, Berlin is known to be one of the cheaper German cities until recently ("poor but sexy"). In addition, the climate, geographies, and economies between LA and Berlin are significantly different.

[ido]

Compare berlin to any big American city and you would see that the rent-to-purchase-prices ratio is always much lower in berlin.