According to Ben Eisen, writing in the Wall Street Journal, Fannie Mae and Freddie Mac are increasingly backing loans to borrowers who have heavier debt loads, highlighting questions about mortgage risk as policymakers debate ways to change the system.

Eisen writes that, according to IMF data, the share of homeowners with high debt-to-income ratios above 43% has nearly doubled since 2015. 

From the article:

The backing of these loans opens up a debate about the government’s role in the housing market. Some say cheap, federally backed financing has made credit available for millions of borrowers who otherwise might not have had a shot at homeownership. Others say that more-indebted borrowers are riskier, and that their purchases may be accentuating a rise in home prices that in many areas has outstripped median incomes.

Those contrasting views are spilling into the open as policy makers once again try to overhaul the housing-finance system. Mark Calabria, the recently confirmed head of the Federal Housing Finance Agency, which oversees Fannie and Freddie, said he plans to prioritize addressing this issue, though he hasn’t said specifically what he wants to do. A White House memo on housing-finance reform, released in March, also mentions it.