The main problem is that most high level - high skilled jobs are now in 2-3 of the biggest cities in Italy, and now everyone is trying to move there and so even more companies try to move their HQs there, and so on. I think a similar problem is happening also in others EU states.
> number of unskilled migration coming from countries like Syria and Afghanistan to Berlin
These people cluser in the city districts ruled by Middle Eastern organized crime (if you ask Germans, no such phenomenon exists). There, market forces don't apply and housing market is hermetic to the outsiders - and it doesn't matter because you wouldn't want to live there.
Then cancel you rental contract, rent something new again and now... if not homeless (or stuck with airbnb)... re-estimate what the decent salary would be.
Mr. Big Shot
Rent control + increasing wealth of the economy is crowding areas and limiting to bid for new renting spaces.
The only city I am aware of with rent control in Europe is Stockholm. Apparently finding a flat there is a nightmare. Where I live there is no rent control and its still a nightmare trying to find somewhere central to rent for a decent price.
You can get a firsthand contract for spatious 2 room apartment in Märsta for 14k a month right now.
At the end of our last 5 year contract the rent went up by around 45%. Bought a small place further out instead.
I'm in a US Rust Belt city that's lost population since the 1950s, and had flat growth in the region since 1970.
Yet in many neighborhoods housing prices have doubled to quintupled over the past 15 years.
Similar stories in a lot of other rust belt areas which I know are not booming. The urban areas are definitely more attractive than they used to be, but it doesn't add up. It makes me think the drive behind this is post-financial crisis monetary policy.
(Still at a very high absolute level.)