Renters' leverage in the market is shifting. A recent change in the national rental vacancy rate suggests this trend. The rate has increased to 7.3 percent.

This increase is compared to a rate of 5.6 percent four years prior. Rental listings offering concessions have become more common, with nearly 40 percent offering incentives.

Further information on this shift and its implications for renters can be found through the U.S. Census Bureau and Zillow.