Starting in July, homeowners in Palma, on the Balearic Island of Mallorca, will not be allowed to rent out their apartments to tourists.The capital of the popular Mediterranean destination has adopted a pioneering measure in Spain, where other cities are also struggling with the consequences of mass tourism, including overcrowded centers and soaring rent. Studies show that the number of unlicensed tourist apartments on offer grew 50% between 2015 and 2017 to reach 20,000 units. In Palma, which is Spain’s eighth-largest city by population, only 645 properties used for short-term vacation rentals have proper licenses. The problem of affordable rent in Palma has been raised not only by residents but also by workers who commute to Mallorca from mainland Spain. City officials say that while vacation rentals are not the sole cause, they are a factor in the 40% rise in average rental prices since 2013.