Record foreclosures and limited access to credit will make it harder than usual to rebound from this U.S. housing market slump, the worst at least since World War Two, according to a Harvard University study on Monday.

A two-year home price drop is eating into housing wealth, curbing consumer spending and slicing away economic growth. This is unlikely to change until potential home buyers are convinced that prices have stopped tumbling, the study found.

The downturn has room to run.