I propose a high tax on empty properties - just what will it bring:
- a reduction in property prices (good for young families and birth rates)
- an end to the grey rental market (good for the state too, I think - VAT)
- the property market would be revived - also good for the economy as a whole
- etc, etc
 
But really, the lobby is probably too strong, so again a few people are making sure that this doesn't happen for a while (new property law).
 
Finally, a question: how can it be that one "real estate tycoon" has 10 or even 100 apartments, but a young family cannot get to it because it is too expensive. Sad isn't it!!!