JudgeIt is a computer program for evaluating election returns and redistricting plans. Gary King and I wrote it around 1990 for the purpose of estimating seats-votes curves for congressional and state legislative elections, and at the same time adapted it to do other things such as district-by-district forecasting. Gary and others have used it many times since to evaluate actual redistricting plans (in actual court cases, or so I’ve heard). The method is described in detail in our 1994 AJPS paper–it’s simple enough that we reprogrammed the basics from scratch in this paper on the 2006 House–but it’s convenient to have it already programmed.
Anyway, Andrew Thomas and Gary translated Judgeit into R, and here it is! It’s all open-source and so we’re hoping people will improve it and criticize it as well as make it easier to use. The next step is to link it with a big database of elections. Also, we’d like to update our 1994 APSR paper to estimate the effects of the 1990 and 2000 redistrictings–people say that these were more nefarious, anti-competitive affairs than in the past, but my guess is that when we crunch the numbers, we’ll find again that redistricting (usually) enhances democracy.