The Methodical Study of PoliticsbyBruce Bueno de MesquitaNYU and Hoover InstitutionOctober 30, 20021The Methodical Study of PoliticsBruce Bueno de MesquitaEcclesiastes teaches that “To everything there is a season and a time for every purpose under the heaven.” Although methodological seasons come and go, I believe most students of politics are united in their purpose. We want to understand how the world of politics works. Some may be motivated in this purpose by a desire to improve, or at least influence, the world, others to satisfy intellectual curiosity, and still others by mixes of these and other considerations. Within the generally agreed purpose for studying politics, however, there are important differences in emphasis that lead to variations in methodological choices. For instance, those concerned to establish the verisimilitude and precision of specific conjectures about particular political events are likely to choose the case study method and archival analysis as the best means to evaluate the link between specific events and particular explanations. Those concerned to establish the general applicability or predictive potential of specific conjectures are likely to choose large-N, statistical analysis as the best means to evaluate the link between independent and dependent variables. Those concerned to probe normative arguments or to engage in social commentary will find other methods, such as post-structuralism and some forms of constructivism, more fruitful. Whatever the explanatory goal and whatever the substantive concern, research benefits from efforts to establish the rigorous logical foundation of propositions as it is exceedingly difficult to interpret and build upon commentary or analysis that is internally inconsistent. The concern for logical rigor to accompany empirical rigor encourages some to apply mathematics to the exploration of politics Mathematical models – whether they are structural, rational choice, 2cognitive, or other forms – provide an especially useful set of tools for ensuring logical consistency or uncovering inconsistencies in complex arguments. As most of human interaction is complex –– and certainly political choices involve complex circumstances –– mathematical modeling provides a rigorous foundation for making clear precisely what is being claimed and for discovering unanticipated contingent predictions or relations among variables. By linking careful analysis or social commentary to logically-grounded empirical claims we improve the prospects of understanding and influencing future politics. The mathematical development of arguments is neither necessary nor sufficient for getting politics right, but it does greatly improve the prospects of uncovering flaws in reasoning. As such, mathematics does not, of course, provide a theory of politics anymore than natural language discourse is itself a theory of politics. Rather, each – mathematics and natural language – is simply a tool for clarifying the complex interactions among variables that make up most prospective explanations of politics. The advantage of mathematics is that it is less prone to inconsistent usage of terms than is ordinary language. Therefore, it reduces the risk that an argument mistakenly is judged as right when it relies – probably unwittingly – on changes in the meaning of terms.A dichotomy has been drawn by some between those who choose problems based on methodological tastes and those who choose methods based on substantive concerns. This seems to me to be a false dichotomy. As intimated above, different methods are appropriate for differentproblems or to demonstrate different facets of an argument. I cannot imagine any serious student of politics who is driven to study problems primarily because they fit a particular method. Rather, it is likely that substantive interests propel researchers to rely more on some methods than others. Of course, all researchers are limited in their skills in using some tools of research as3compared to others. This too surely plays a role in the selection of research tools applied to substantive problems. It is, for instance, particularly difficult for those lacking the requisite technical training in a method, whether it be mathematical modeling, archival research, experimental design, or statistical analysis, to adapt to the use of unfamiliar, technically demanding tools. We need not, however, concern ourselves here with this limitation as its remedies are straightforward. Researchers can retool to acquire the methodological skills needed for a research problem or they can select collaborators with the appropriate technical know-how. Naturally, the costlier retooling is in time and effort, the less likely it is that the researcher will pay the price and the more likely it is that appropriate co-authors will be chosen. Co-authorship is an increasingly common practice in political science presumably for this reason. With these few caveats in mind, I put the dichotomy between methodological tastes and substantive interestsaside and focus instead on what I believe are the linkages between substantive issues and methodological choices.Clearly, when researchers fuse evidence and logic, they improve our ability to judge whether their claims are plausible on logical grounds and are refuted or supported empirically. This combination of logic and evidence has been the cornerstone of studies of politics over more than two millennia. Such an approach typifies the writings, for instance, of Aristotle, Thucydides,Kautilya, Sun Tzu, Acquinas, Machiavelli, Hobbes, Hume, Locke, Madison, Montesquieu, Marx,Weber, Dahl, Riker, Arrow, Black and on and on. Reliance on the tools of rhetoric or on advocates’ briefs without logic and balanced evidence probably makes evaluating research more difficult and probably subject to higher interpersonal variation than when relying on logic and evidence. With this in mind I begin by considering what forms of argument and evidence are most likely to advance knowledge and persuade disinterested observers of the merits or 4limitations of alternative contentions about how politics works. As I proceed, I will occasionally offer illustrative examples. When I offer such examples they will be drawn primarily from research on international relations as this is the aspect of political research best known to me.The Case Study Method of AnalysisOne path to insight into politics is through the