MIAMI—In Miami, there is at least 4 million square feet of retail space in the permitting stages and under construction. What does that say about the Miami's retail sector? Plenty, according to Andrew Hellinger, the developer behind River Landing Shops and Residences on the Miami River west of Downtown Miami.

“This says Miami Dade is a hotbed of retail activity to serve the rapid population growth,” Hellinger says. “Last year, Florida's population surpassed New York's.”

That's not news, but it's a big selling point for retailers. Hellinger points to another economic driver: 97.3 million tourists visited Florida, a 3.9% increase from 2013. Most of the action is in Miami-Dade, where the population grew by 21,000 people just last year.