Herron, Mebane and Wand: "Voting Technology and the 2008 New Hampshire Primary"

Earlier this week Michael Herron sent along a copy of the working paper that he has written with Walter Mebane and Jonathan Wand, in which they dig into some of the allegations of irregularities in the recent New Hampshire primary (here’s a link to the most recent version.)

It’s an interesting paper, and well done. The paper’s executive summary provides a good overview of their argument:

We address concerns that the reported vote counts of candidates running in the 2008 New Hampshire Presidential Primaries were affected by the vote tabulating technologies used across New Hampshire.

• In the Democratic Primary, Hillary Clinton was more successful in New Hampshire wards that used Accuvote optical scan vote tabulating technology than was Barack Obama, receiving 4.3 more percentage points of the vote there (40.2% for Clinton versus 35.9% for Obama). In contrast, Clinton did worse than Obama in wards that counted paper ballots by hand, trailing by 6.1 percentage points (33.7% versus 39.8%).

• In the Republican Primary, Mitt Romney trailed John McCain by 3.6 points in Accuvote wards and by 15 points in wards that counted ballots by hand.

• In New Hampshire the choice of vote tabulating technology is made ward by ward, and electronic technology was used in wards that typically differ demographically and politically from wards that count ballots by hand. Wards that selected electronic tabulation are disproportionately from the southeast part of New Hampshire, and they tend to be more densely populated and more affluent. Accuvote and hand count wards have also typically produced divergent voting patterns in elections prior to the 2008 primary. It is plausible that most or all of the observed differences between vote tabulating technologies in the votes candidates received reflect such background differences and not anything inherent in the tabulation methods.

• Using a subset of New Hampshire wards that have similar demographic features and voting histories but differ in their vote tabulating technologies, we find no significant relationship between a ward’s use of vote tabulating technology and the votes or vote shares received by most of the leading candidates who competed in the 2008 New Hampshire Presidential Primaries. Among Clinton, Edwards, Kucinich, Obama and Richardson in the Democratic primary and Giuliani, Huckabee, Paul, Romney and McCain in the Republican primary, we observe a significant difference only in the votes counted for Edwards, and that difference is small (a deficit of between 0.6 and 3.4 percent in the hand-counted votes).

• With respect to Hillary Clinton’s surprise victory in the Democratic Primary and the differences across vote tabulating technologies in Clinton’s and others’ votes, our results are consistent with these differences being due entirely to the fact that New Hampshire wards that use Accuvote optical scan machines have voters with different political preferences than wards that use hand counted paper ballots.

Well worth reading!