The Probability of Being President
在传统预期得票率模型中加入风险计算，将其分解为系统性和非系统性成分，发现系统性风险对总统选举至关重要，并揭示了州际投票波动的相关性。
Economic models of politics typically use the expected value of a candidate's vote share to proxy electoral probability. In this paper, the authors introduce a risk calculation to augment the evaluation of a candidate's (or party's) expected vote share and they divide this risk element into its systematic and unsystematic components. For the same reason that systematic risk is a primary focus of portfolio management, the authors discover that an analogous systematic risk component is central to presidential elections. Their approach accounts for correlations in vote swings among states, piercing the fiction of a state-by-state or 'local' campaign strategy. Copyright 1993 by MIT Press.