A clear rule decides congressional elections: whoever gets the most votes in November wins. Because virtually every congressional race in the United States is between two parties, whoever gets more than 50% of the vote wins. We can use this fact to determine if Republican (or Democrat) elected members of Congress follow the average ideology of their constituents (i.e., the median voter theory) or if they deviate in ideology because of the party they belong to. (In other words, do elected members of Congress follow the people or their party?)
Some argue that Republicans and Democrats are very distinctive; others say that members of Congress have a strong incentive to respond to the median voter in the district, regardless of party. We can assess how much party matters by looking at the ideology of members of Congress in the 112th Congress (which covers the years 2011 and 2012). (We define the median voter as the voter that represents the median ideology of the population).
Ideology measures the “conservatism”/”liberalism” of the members of Congress. This measure was developed by Carroll et al. (2009, 2014). It ranges from -0.779 to 1.293. Higher values indicate more conservative voting in Congress. Share of vote Republican is the percentage of the vote received by the Republican congressional candidate in districts. Ranges from 0 to 1.
- If the elected member of Congress is to the left of the threshold, what party do they belong to?
- Democrat
- Republicans
- If the elected member of Congress is to the right of the threshold, what party do they belong to?
- Democrat
- Republicans
- What is the running variable?
- Percentage of people that go vote
- A dummy variable if republican won or not
- Share of votes for Republican candidate
- The conservatism of the candidate
- What is the outcome variable?
- A variable measuring distance from 50% share of republican voting
- Ideology voting of the elected member of congress
- Being Republican
- Being Democrat
- Given the research question from the prompt, what is the treatment?
- Being conservative
- Being less conservative
- Being from a particular party (R or D) and elected member of Congress
- Is this a sharp or fuzzy discontinuity?
- Sharp
- Fuzzy
- The results from this RD provide empirical evidence that strengthens which theory:
- Congress members respond to the political party.
- Congress members respond to the median voter.