The Miami Herald is reporting that most South Florida residents can't afford to buy condos in Miami. 

Condos are being bought by from people around the world including South Americans, Russians and French etc. 

In the last condo boom most people were buying condos with almost zero down payments and when the real estate bubble burst, developers were left to scramble when buyers started backing out of their deals. To prevent the same situation from happening again, developers are accepting at least 50 percent down payment or all cash offers for a unit. Most Miamians can't afford that kind of payment and in turn end up renting from the global buyer.