CHANGE: Home-Purchase Index in U.S. Plunges to Lowest Level Since 2000. It’s all about regime uncertainty. “Mortgage applications to purchase homes in the U.S. plunged last week to the lowest level in almost nine years as Americans waited for the outcome of deliberations to extend a government tax credit.” While the government dithers over how to jump-start the housing market, the uncertainty created by that dithering kills it . . . .