I think holiday homes are an issue in small villages with a limited housing stock, but I think simply buying for speculation is the far bigger problem in the cities. I went to visit a friend in Budapest and both her and her sister are living in flats that are basically half the size that they used to be. Lot's of the old buildings are being bought by investors and converted into much smaller flats, but the rents are actually increasing. AirBNB has become a thing because of the huge prices that hotels charge nowadays, which is a symptom of the same thing. It's hard to get a hotel room in a big city nowadays for less than £50 a night, so unless you want to sleep in a hostel, you go to AirBNB. In Italy, we stayed in AirBNB almost the whole time and the one time we stayed in a hostel, it was actually more expensive. But like immigrants, tourists are just another diversion from the real problem, which is investors, often not from the area, buying up property, causing rocketing house prices and in many cases, leaving them empty.