Brian Knight and Nathan Shiff have a “paper”:http://weber.ucsd.edu/~jlbroz/PElunch/knight_schiff_momentum.pdf on momentum and voter choice.
This paper provides an investigation of the role of momentum and social learning in sequential voting systems. In the econometric model, voters are uncertain over candidate quality, and voters in late states attempt to infer the information held by those in early states from voting returns. Candidates experience momentum effects when their performance in early states exceeds expectations. The empirical application focuses on the responses of daily polling data to the release of voting returns in the 2004 presidential primary. We find that Kerry benefited from surprising wins in early states and took votes away from Dean, who held a strong lead prior to the beginning of the primary season. The voting weights implied by the estimated model demonstrate that early voters have up to 20 times the influence of late voters in the selection of candidates, demonstrating a significant departure from the ideal of “one person, one vote.” We then address several alternative, non-learning explanations for our results. Finally, we run simulations under different electoral structures and find that a simultaneous election would have been more competitive due to the absence of herding and that alternative sequential structures would have yielded different outcomes.
I’ve not even a scintilla of the technical expertise that would be required to assess the claims of the paper. And they could certainly have chosen a better election year to make it in (later votes in the primary process clearly count for quite a bit more than usual this time around). But the basic underlying argument – that peoples’ primary votes in Iowa will usually count for some multiple of the influence that people’s votes in, say, Pennsylvania count for, seems to me to almost certainly be true. So is this something that people should be concerned with on basic grounds of equity etc? Does this provide enough grounds that people should push for reform (either through having all primaries on one day, or perhaps semi-randomizing the allocation of slots in the calendar if that isn’t feasible)?
Obviously, there are similar inequities in the apportionment of US Senate seats by population – but that is built into the system by design, and can’t be gotten rid of without constitutional change. Calendaring is in the remit of the parties and the states themselves. My memory is that a couple of states benefitting from the current set-up have sought to make their threats more credible through amendments to their domestic constitutions, but I am skeptical that these commitments would in fact be credible if every one else converged on a single date or changed system. This is, indeed, one of those cases where we would be better off if the simplest one-shot game theory prediction came true (i.e. the outcome in which every state party converges on the equilibrium of the earliest possible date). So would this be a bad idea?
