A Model Disagreement

A Model Disagreement Stephen M. Walt My purpose in writing “Rigor or Rigor Mortis?” was to evaluate the contributions of formal rational choice theory to the ªeld of security studies.1 I argued that formal theory was useful—but not essential—for developing precise and logically sound arguments, and suggested that the beneªts of formalization were not cost-free. I also argued that recent formal work had not produced a signiªcant body of new and original insights, and I sought to show that much of this work was either untested or empirically questionable. Accordingly, I concluded that although formal theory could be a valuable part of theªeld, it was not intrinsically superior to other well-established research techniques. As a result, I emphasized that the ªeld of security studies should strive to maintain its methodological pluralism. To paraphrase Georges Clemenceau , the study of warfare is too important to be left solely to formal modelers. The ªve responses to my article raise many important issues. Lacking sufªcient space to address all of them, I focus here on the central points that divide us. I do not believe that the responses cast serious doubt on my original claims, and as I attempt to show below, several of them actually provide additional support for my position. My reply consists of ªve sections. The ªrst section considers the issue of logical consistency and precision, which several of the respondents declare to be the most important feature of a scientiªc theory and the cardinal virtue of formal techniques. The second section examines the question of creativity and originality and shows why the examples of innovative work offered by my critics do not undermine my original assessment. The third section revisits the issue of empirical validity and shows that the responses actually lend further support to my central argument. The fourth section addresses the crucial issue of policy relevance, which is still a major liability of formal work in the ªeld of security studies. The ªfth section considers the hegemonic aspirations of the modeling community and reiterates my plea for methodological pluralism. International Security, Vol. 24, No. 2 (Fall 1999), pp. 115–130© 1999 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology. 115 Stephen M. Walt is the Evron M. and Jeane J. Kirkpatrick Professor of International Affairs at the John F. Kennedy School of Government, Harvard University. 1. Stephen M. Walt, “Rigor or Rigor Mortis? Rational Choice and Security Studies,” International Security, Vol. 23, No. 4 (Spring 1999), pp. 5–48. Further references appear parenthetically in the text. Logical Consistency and Precision The responses to my article make two main claims on the subject of logical consistency and precision. The ªrst claim is that I place little value on this criterion, thereby stacking the deck against formal modeling.2 The second claim is that logical consistency is the sine qua non of any scientiªc theory, a claim intended to demonstrate the intrinsic superiority of formal techniques. The ªrst charge is false; the second merits additional discussion. Contrary to the ªrst assertion, I do not denigrate logical consistency or precision. As I wrote in my article, social science “requires theories that are logically consistent, precise, original, and empirically valid.” I also declared that “other things being equal, theories that are stated precisely and that are internally consistent are preferable to theories that are vague or partly contradictory ,” adding that “logical consistency is highly desirable and efforts to achieve it are a central aim of science.” And I went to some lengths to point out that this was an area where formalization could make a contribution (pp. 8, 12, 17). Like motherhood and apple pie, in short, logical consistency is something that all of us endorse. Where we differ is in the relative importance of this criterion and the relative performance of formal and nonformal approaches. Several respondents assert that logical consistency is the most important criterion for judging a social science theory. This view is clearest in the response by Bruce Bueno de Mesquita and James Morrow, who write that “logical consistency takes precedence over [creativity and empirical validity],” adding that it enjoys “pride...