The Mortgage Bankers Association, in a letter to Federal Housing Finance Agency Director Mark Calabria, urged caution on a proposed “waterfall approach” to pooling practices used by Fannie Mae and Freddie Mac in the Uniform Mortgage-Backed Security market, saying in its current form the proposal could have a “negative effect” on market liquidity, raise borrowing costs and reduce access to credit.

What goes up, must come down. Following a stellar start to the month last week, in which mortgage applications jumped by more than 30 percent after the New Year’s holiday, the pendulum swung back slightly.

On Jan. 17, Consumer Financial Protection Bureau Director Kathy Kraninger sent a letter to members of Congress, signaling proposed changes to the current Qualified Mortgage standard.

This week’s MBA Chart of the Week examines the reasons why fewer Americans are moving.