A new Urban Institute study says that tight credit standards curbed mortgage lending activity from 2009 to 2013.

Based on the authors’ estimates, if the cautious standards of 2001 had been in place rather than the more severe standards that were in place over these five years, lenders would have made more than 4 million additional loans.

“The number of potential loans that were not made-which we call ‘missing loans’-grew from 0.50 million in 2009 to 1.25 million in 2013. African American and Hispanic families have been particularly affected by this tight credit environment,” the authors say.

The full study can be read here