Electoral design and voter welfare from the US Senate: Evidence from a dynamic selection model

Since 1914, the US Senate has been elected and incumbent senators allowed to run for reelection without limit. This differs from several other elected offices in the US, which impose term limits on incumbents. Term limits may harm the electorate if tenure is beneficial or if they force high quality candidates to retire but may also benefit the electorate if they cause higher quality candidates to run. We investigate how changes in electoral design affect voter utility by specifying and structurally estimating a dynamic model of voter decisions. We find that tenure effects for the US Senate are negative or small and that incumbents face weaker challengers than candidates running for open seats. Because of this, term limits can significantly increase voter welfare.