20 June 2007
The Society for Political Methodology has announced the winner of its inaugural Career Achievement Award. The first recipient will be Chris Achen, currently the Roger Williams Straus Professor of Social Sciences at Princeton University. The award will be presented at the APSA meeting this summer at the society's business meeting. Chris was chosen to receive the award by a committee consisting of Simon Jackman, Mike Alvarez, Liz Gerber and Marco Steenbergen, and their citation does a fine job of summarizing his many accomplishments over the years.
On a personal note, Chris was my senior thesis advisor back in 00-01 when he was at Michigan. That came about through a bit of luck; I had never taken a class from him, and one of the other professors at Michigan asked him to meet with me as a favor. Despite this, he was unfailingly generous with both support and constructive criticism. At least at the time, Chris had the habit of working rather late in the evenings. When I was working on my thesis, I'd often send him an e-mail asking a few questions when I left the computer lab at night, and by the time I got home there would be an answer in my inbox pointing out what I had missed or suggesting some new approach to try. If Chris hadn't taken me on as an advisee back then, I probably would not be in graduate school today.
The citation follows on the jump:
Christopher H. Achen is the inaugural recipient of the Career Achievement Award of the Society for Political Methodology. Achen is the Roger William Straus Professor of Social Sciences in the Woodrow Wilson School of Public and International Affairs, and Professor of Politics in the Department of Politics, at Princeton University. He was a founding member and first president of the Society for Political Methodology, and has held faculty appointments at the University of Michigan, the University of California, Berkeley, the University of Chicago, the University of Rochester, and Yale University. He has a Ph.D. from Yale, and was an undergraduate at Berkeley.
In the words of one of the many colleagues writing to nominate Achen for this award, "Chris more or less made the field of political methodology''. In a series of articles and books now spanning some thirty years, Achen has consistently reminded us of the intimate connection between methodological rigor and substantive insights in political science. To summarize (and again, borrowing from another colleague's letter of nomination), Achen's methodological contributions are "invariably practical, invariably forceful, and invariably presented with clarity and liveliness''. In a series of papers in 1970s, Chris basically showed how us how to do political methodology, elegantly demonstrating how methodological insights are indispensable to understanding a phenomenon as central to political science as representation. Achen's "little green Sage book'', Interpreting and Using Regression (1982) has remained in print for 25 years, and has provided generations of social scientists with a compact yet rigorous introduction to the linear regression model (the workhorse of quantitative social science), and is probably the most widely read methodological book authored by a political methodologist. Achen's 1983 review essay "Towards Theories of Data: The State of Political Methodology'' set an agenda for the field that still powerfully shapes both the practice of political methodology and the field's self-conception. Achen's 1986 book The Statistical Analysis of Quasi-Experiments provides a brilliant exposition of the statistical problems stemming from non-random assignment to "treatment'', a topic very much in vogue again today. Achen's 1995 book with Phil Shivley, Cross-Level Inference, provides a similarly clear and wise exposition of the issues arising when aggregated data are used to make inferences about individual behavior ("ecological inference''). A series of papers on party identification --- an influential 1989 conference paper, "Social Psychology, Demographic Variables, and Linear Regression: Breaking the Iron Triangle in Voting Research'' (Political Behavior, 1992) and "Parental Socialization and Rational Party Identification'' (Political Behavior, 2002) --- have helped formalize the "revisionist'' theory of party identification outlined by Fiorina in his 1981 Retrospective Voting book, and now the subject of a lively debate among scholars of American politics.
In addition to being a productive and extremely influential scholar, Achen has an especially distinguished record in training graduate students in methodology, American politics, comparative politics, and international relations. His students at Berkeley in the late 1970s and early 1980s included Larry Bartels (now at Princeton), Barbara Geddes (UCLA), Steven Rosenstone (Minnesota), and John Zaller (UCLA), among many others. His students at Michigan in the 1990s include Bear Braumoeller (now at Harvard), Ken Goldstein (Wisconsin), Simon Hug (Texas-Austin), Anne Sartori (Princeton), and Karen Long Jusko (Stanford). In addition to being the founding president of the Society for Political Methodology, Chris has been a fellow at the Center for Advanced Study in the Behavioral Sciences, has served as a member of the APSA Council, has won campus-wide awards for both research and teaching, and is a member of the American Academy of Arts and Sciences.
13 June 2007
A few days ago, the AP moved a story reporting on academic studies of the deterrent effect of the death penalty on potential murderers. Many media outlets picked up the story under headlines such as "Studies say death penalty deters crime", "Death penalty works: studies", and my favorite, "Do more executions mean fewer murders?" Presumably the answer to the last question is yes, at least in the limit; if the state were to execute everyone (except the executioner, of course), clearly there would be fewer murderers.
I was surprised when I read the article on Monday morning, since my sense of the state of play in this area is that it is probably impossible to tell one way or the other. Those are the findings of a recent study by Donohue and Wolfers, which finds most existing studies to be flawed and, more importantly, points out a variety of reasons why estimating the correct deterrent effect is difficult in principle. Here is some of what Andrew Gelman had to say about their study last year:
My first comment is that death-penalty deterrence is a difficult topic to study. The treatment is observational, the data and the effect itself are aggregate, and changes in death-penalty policies are associated with other policy changes.... Much of the discussion of the deterrence studies reminds me of a little-known statistical principle, which is that statisticians (or, more generally, data analysts) look best when they are studying large, clear effects. This is a messy problem, and nobody is going to come out of it looking so great.
My second comment is that a quick analysis of the data, at least since 1960, will find that homicide rates went up when the death penalty went away, and then homicide rates declined when the death penalty was re-instituted (see Figure 1 of the Donohue and Wolfers paper), and similar patterns have happened within states. So it's not a surprise that regression analyses have found a deterrent effect. But, as noted, the difficulties arise because of the observational nature of the treatment, and the fact that other policies are changed along with the death penalty. There are also various technical issues that arise, which Donohue and Wolfers discussed.
Given the tone of the article (and certainly the headlines), you would have thought that the Donohue and Wolfers paper had been overlooked by the reporter, but no: he cites it in the article, and he interviewed Justin Wolfers! He seems to have missed the point, however; the issue is not that some studies say that "there is a deterrent effect" and some say "we're just not sure yet". The problem is that we aren't sure, and we probably never will be unless someone gets to randomly assign death penalty policy to states or countries. This raises a problem that we often face in social science: there are questions that are interesting, and there are questions that we can answer, and the intersection of those two categories is probably a lot smaller than any of us would like. This doesn't seem to be a realization that has crept into the media as of yet, so it is no surprise that studies that purport to give answers to interesting questions will get more coverage than those pointing out why those answers probably don't mean very much.
7 June 2007
Congratulations to the 2007 Gosnell Prize winners - Harvard's very own Alberto Abadie, Alexis Diamond, and Jens Hainmueller! They won for their paper "Synthetic Control Methods for Comparative Case Studies: Estimating the Effect of California's Tobacco Control Program", which was presented at this year's MPSA conference in Chicago. We saw an earlier version of the paper this past semester at the Applied Stats workshop, and I have to say, the award is well deserved. The Gosnell Prize is awarded to the best paper presented at any political science conference in the preceding year. Alexis is a two-time recipient, having shared the award with Jas Sekhon in 2005 for their paper on genetic matching.
5 June 2007
Yesterday, StataCorp announced that Stata 10 will be available from June 25. Apart from a bunch of new routines, a main attraction will be their new graph editor which might well resolve major nightmares for users. Also it appears that there is now a way to copy & paste results to other applications without loosing the formating. Overall the new version looks great, if you're so inclined.