Andrew Gelman contemplates strategic retirement:
It’s expected to be a good year for the Democrats, and so now should be the time for them to make some investments in new, young candidates. They should encourage lots of their incumbents to retire, because in 2008, they can win a lot of these districts without needing the incumbency advantage (estimated to be about 10% of the vote, i.e., enough to take you from 50% to 60%). Conversely, this is the time for the Republican Party to hold on to what it has, and to keep all their incumbents in, trying to hold out until 2010 when the pendulum might swing back in their favor. But we don’t see thatactually, something like 30 Republican House members are retiring this year.
Republicans retiring, Democrats sticking aroundthat’s a recipe for big Democratic gains this year. But then in 2010, or 2014, or whatever year it is when the Democrats get wiped outthen a bunch of their incumbents will probably retire, and boy will the Democrats wished they had put in younger incumbents back in 2008 when they had a chance!
One of the difficulties here is that I’m talking about the long-term goals of the parties, but “the parties” are, to a large extent, simply their officeholders. And congressmembers’ incentives can be much different from those of the party as a whole. In particular, it makes sense that an incumbent congressmember will want to quit in a year when he or she would be facing a tough reelection battle, and when the prize for winning is to remain in the minority. Conversely, why step down when you’re facing an easy reelection and the prospect of some juicy committee assignments? So the individual officeholders have an incentive for pro-cyclical behavior, even if it harms their party’s long-term interest.