Recapitalizing Fannie Mae and Freddie Mac is a good idea, according to the Congressional Budget Office, which said that it wouldn’t significantly change how the government-sponsored enterprises operate today, but it would help stabilize the mortgage market and the federal budget. In response to several legislative proposals calling for the GSEs to build capital, the CBO recently published a report studying the effects of an “illustrative policy option.” Fannie and Freddie capital will...