A USC study released this week says Washington, D.C., and California cities have the widest disparity between income and affordability for rental housing.

New research by USC housing experts reveals lack of affordable rent is a bigger problem than previously realized, not only in big coastal cities but across much of the United States, according to a statement released in conjunction with the study.

The findings come from a new method by researchers at the USC Price School of Public Policy to provide policymakers a more accurate picture of rental market conditions. It helps show ratcheting pressure on working people as well as the challenges companies face in recruiting labor. The findings also underscore how traditional methods of calculating rent burden often substantially misrepresent real-world conditions.

“The study shows a growing mismatch of rents and incomes, how rents are rising faster than wages. It’s an affordability problem acute among the poorest people, but it affects a much broader constituency of people,” said Dowell Myers, professor of urban planning and demography at USC Price, and director of the school’s Population Dynamics Research Group.

Washington, D.C., was the least affordable metropolitan area overall in the nation. Four of the 10 least affordable metros are in California: San Diego, Los Angeles, Riverside-San Bernardino and Sacramento. The nation’s most affordable cities are inland, including Atlanta, Salt Lake City, Las Vegas, and Phoenix.

The newly published study appears in the peer-reviewed, policy research journal Cityscape, which is produced by the U.S. Department of Housing and Urban Development.