When Is It Obama’s Economy?

Nate Silver tries to determine when voters will hold Obama accountable:

Obama crosses the 50 percent threshold at almost exactly 18 months from now, which would mean September 2010. At that point, a majority of voters say they will hold Obama accountable for the performance of economy.

Perhaps not coincidentally, 18 months is also about the point at which a majority of voters expect the recession to have ended.