Improving Empirical Applications of the Expected Utility Theory of War

在国际冲突的预期效用预测与实际国际冲突的拟合中，研究人员提出了三个可能的区域和时间变化来源的检查。对理性选择理论在国际冲突中的最复杂的一般实施（基于Bueno de Mesquita和Lalman 1992年的“国际互动游戏”）的测试揭示了该理论预测在时间和空间上的系统变化。这种对所谓“战争预期效用理论”的拟合的意外变化并没有被理论预测到，它对理性选择模型在国际关系、国际冲突研究和国际关系定量分析中的应用具有重要意义。这种变化的系统性质及其明显符合关于学习和区域差异的合理假设，表明这种变化不仅仅是测量不当或自然变化的结果。因此，这些变化应该被解释为一种手段，以获得更准确和经验上适用的执行国际冲突的关键理性模型。任何理性选择模型对时空相互作用的拟合变化至少可以用两种一般方法来解释。首先，一些学者将注意力集中在博弈结构上，拒绝接受国际互动博弈是跨时间所有二元互动的合适理论模型的前提。其次，其他人会认为测量和应用问题是在应用环境中测试和使用预期效用理论的关键，并且在当前关键预期效用概念的测量和操作中存在特殊问题，这些问题对预期效用理论的测试产生了系统性的扭曲作用。这两个可能的问题在这个特殊情况下都有相关性。首席研究员首先计划调查国际互动游戏的游戏结构的关键变化如何影响其预测，以及这些预测与国际冲突行为的契合度。研究者通过关注关键的博弈假设，即所有国家都可以选择对彼此使用武力，并通过开发计算机模拟来放松博弈假设，并重新评估最终的平衡与全球和区域行为模式的契合度。研究者还检查了当前操作化和关键预期效用概念实施中涉及的关键测量问题。特别是，密切关注距离和绝对国家权力的影响，作为国际互动游戏的预测不符合广泛经验应用预期的关键决定因素。这项工作部分借鉴了尤金（预期效用和数据生成程序）开发过程中获得的见解，该软件包用于生成数据，以充分测试国际互动游戏的预测（Bennett和Stam 1997, 1998）。

The researcher proposes an examination of three likely sources of regional and temporal variation in the fit of expected utility predictions of international conflict to actual international conflict. Tests of the msot sophisticated general implementation of rational choice theory to international conflict (based on Bueno de Mesquita and Lalman's 1992 "international interaction game") reveal systematic variations in the fit of the predictions of the theory across time and space. This unexpected variation in the fit of the so-called "expected utility theory of war" is not predicted by the theory, and it has importance implications for the application of rational choice models to international relations, to the study of international conflict, and to quantitative analysis in international relations. The systematic nature of the variation and its apparent fit to plausible hypotheses about learning and regional diffferences suggest that the variation is not solely the result of poor measurement or natural variation. As a result, these variations should be explained as a means of obtaining a more accurate and empirically applicable implementation of a key rational model of international conflict. Variation in the fit of any rational choice model to interactions across time and space could be explained by at least two general approaches. First, some scholars would focus attention on the game structure, refusing to accept the premise that the international interaction game is an appropriate theoretical model of dyadic interaction for all dyads across time. Second, others would argue that measurement and application issues are the keys to testing and using expected utility theory in an applied setting, and that there are particular problems in the current measurement and operationalization of key expected utility concepts that have systematic distorting effects on tests of expected utility theory. Both of these possible problems have relevance in this particular case. The principal investigator first plans to investigate how critical changes in the game structure of the international interaction game affect its predictions and the fit of those predictions to international conflict behavior. The investigator does this by focusing on the key game assumption that all states have the option to use force against one another, and also by developming a computer simulation intended to relax game assumptions sequentially and to reassess the fit of the resulting euilibria to global and regional behavior patterns. The investigator also examines critical measurement issues involved in the current operationalization and implementation of key expected utility concepts. In particular, close attention is given to the effects of distance and absolute state power as key determinants of why the predictions of the international interaction game do not fit as expected in broad empirical application. This work draws in part on insights gained during the development of EUGene (Expected Utility and Data Generation Program), the software package used to generate data to test fully the predictions of the international interaction game (Bennett and Stam 1997, 1998).