Andrew Gelman discusses a paper by Jan Leighley and Jonathan Nagler, in which they find that differences between voters and non-voters in terms of policy preferences are larger than those found in the canonical research of Ray Wolfinger and colleagues, including Steven Rosenstone and Ben Highton. Gelman suggests, “It would be good to resolve the disagreement between the different experts in this area.”paper by John Griffin and Brian Newman, as well as two papers by Larry Bartels and Marty Gilens, respectively, on the responsiveness of leaders to constituents with higher incomes).
Where does this leave us? With a nascent resolution, I think. Non-voters are more Democratic than voters, though the uncompetitive nature of many elections means that even compulsory turnout wouldn’t produce many more Democratic victories. The policy preferences of non-voters are also more liberal than those of voters, and this may have some consequence for policy (though here I think the research is less well-developed, especially compared to that about election outcomes).
Another consideration here is that social science may not be able to fully comprehend the effects of something like compulsory turnout. How would this kind of shift change the political landscape? We don’t really know. For example, we don’t know if this would affect how candidates and parties position themselves and the kinds of messages they send. It’s possible that the aggregate preferences of the entire electorate might be more different than those of voters today, in part because of campaign effects. And it is also possible that elected leaders would pursue different policies while in office, given the expanded electorate to which they would have to answer once the campaign begins.
If we are to speak to these kinds of possibilities, political scientists need more creative simulations or empirical analyses than we have thus far developed.