Ferejohn: Incumbent performance and electoral control
Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I even say who wrote them. If you have more recent summaries to add to this collection, send them my way I guess. Sorry for the ads; they cover the costs of keeping this online.
Ferejohn. 1986. Incumbent performance and electoral control. Public Choice 30 (fall): 5-25..
Voters can't trust anybody's campaign promises. Thus, challengers don't influence voters: voters simply have a referendum on the incumbent. They use retrospective voting: they vote based on what the incumbent has done for them lately. If they don't like the incumbent, they vote him out, effectively selecting a new representative at random from a pool of equally untrustable challengers. For this to work, voters must not vote selfishly--they most employ "sociotropic voting": "that is, voting based on an aggregate criterion." Elections are for sanctioning moral hazard, not for preventing adverse selection.
- Rational, self-interested voters (and candidates) and an electorate with homogeneous preferences (i.e. sociotropic voting).
- The officeholder is imperfectly monitored by the electorate.
- Candidates cannot make credible campaign promises because voters assume that they will act self-interestedly once in office. Thus, the challenger can be anybody, and his appeal is merely his presence. Elections are just a referendum on the incumbent.
- Given all this, voting is purely retrospective (i.e. strong economy, avoidance of major wars). However, since voters cannot perfectly monitor the incumbent, they do not observe actual policy; instead, they observe conditions (which combines policy and exogenous occurences) and judge incumbents accordingly.
- Incumbents will work harder at reelection (i.e. responsiveness) if the office is more valuable.
- If there are fewer parties in competition, the incumbent has a better chance of regaining office even if he loses office now (because the next election will be an incumbent on the other parties, with a new winner chosen randomly from the out-parties; fewer out-parties means better probability of regaining power). Thus, accountability is better served by a larger number of parties.
- If voters aren't sociotropic (i.e. don't have homogenous preferences), incumbents can play one section of the electorate against another, dramatically reducing electoral accountability.