Bafumi and Herron on whether the US government is representative 

 Amid the name-calling, insinuation and jingoism of this political season it is easy to get a bit depressed about the democratic process. Joe Bafumi and Michael Herron have an interesting working paper that is cause for some comfort. The paper, entitled " Preference Aggregation, Representation, and Elected American Political Institutions ," assesses the extent to which our federal political institutions are representative, in the sense that elected officials have similar views to those of their constituents. They do this by lining up survey questions from the Cooperative Congressional Elections Study (recently discussed in our weekly seminar by Steve Ansolabehere) alongside similar roll call votes recorded for members of Congress, as well as President Bush's positions on a number of pieces of legislation. There are enough survey questions to be able to place the survey respondents on an ideological scale (using Bayesian ideal point estimation), enough pieces of legislation to place the members of Congress and the President on an ideological scale, and enough survey questions that mirrored actual roll call votes to bring everyone together on a unified scale.  

 Overall, the authors find that the system is pretty effective at aggregating and representing voters' preferences. Members of Congress are more extreme than the constituencies they represent (perhaps because they represent partisans in their own districts), but the median member of a state's delegation is usually pretty close to the median voter in that state. Since the voters were surveyed in 2006, the paper is able to look at how the election affected the ideological proximity of government to the voters, and as one would hope Bafumi and Herron find that government moved somewhat closer to the voters as a result of the legislative reshuffling. 

 Below is one of the interesting figures from the paper. The grey line shows the density of estimated ideal points among the voters (ie CCES survey respondents); the green and purple solid lines are the density of estimated ideal points among members of the current House and Senate. The arrows show the location of the median member of the current and previous House and Senate, the median American at the time of the 2006 election (based on the survey responses), and President Bush. As you can see, before the 2006 election the House and Senate were both to the right of the median American (as was President Bush); after the Democratic sweep Congress has moved closer to the median American. Members of Congress are more partisan than the voters throughout, although this seems to be more the case on the right than the left.