It started happening 2-3 years ago in eastern Europe too, or at least here in Serbia. I heard a story/theory that it's not people who are buying up the market, but companies. They drive up the demand and prices and keep buying at a loss, so that when there is virtually no free real estate in area anymore they start renting it out at exorbitant prices. It kind of makes sense consider how empty most new buildings, that sold out, are. Then again could be rich people investing (money laundering) in real estate.