Jacob Hacker has argued that income volatility has been increasing and that Americans are exposed to more economic risk than they used to be, and that liberal policies are required to provide some security. (I bought Hacker’s empirical case, but not his policy prescriptions.) The Congressional Budget Office recently released a report suggesting that individual income volalility hasn’t been increasing.

Hacker, in response , argues that the volatility of family income has been rising. Tyler Cowen notes how much weaker a claim that is; Ross Douthat argues that Hacker has been “taking data that would seem to support the socially conservative contention that changing family structure has had a lot of negative externalities for vulnerable Americans, and using it to claim that 1) Republicans have shredded the safety net and 2) we need a much, much stronger one than what we currently have.”