The Consumer Financial Protection Bureau thinks that people should not take on mortgages that they cannot afford. As explained in
this Washington Post article, the CFPB today will issue new rules to protect consumers from high-risk mortgage borrowing. Among other things, the rules will define a "qualified mortgage" and say that a consumer cannot obtain a qualified mortgage if her debt burden exceeds 43% of her income. We will update this post with the rules themselves as soon as we have them.