Legislation introduced in the last weeks of the 114th Congress would push Fannie Mae and Freddie Mac deeper into the risk-sharing pool, including forcing them into a front-end structure they have so far resisted. The “Taxpayer Protections and Market Access for Mortgage Finance Act of 2016” would require the Federal Housing Finance Agency to push the two government-sponsored enterprises to transfer at least 400 basis points of their total risk. While it’s not clear how the legislation intends this to be measured, it appears...