The Persistent Presidential Dummy
指出一项声称民主党总统任期股市表现更好的研究存在统计方法缺陷，修正后两党差异不显著，强调正确研究设计的重要性。
Is a Republican or a Democratic party president better for the stock market? Although many observers discuss this issue in only casual terms, one recently published academic study claims to have documented that the market does significantly better under Democratic party administrations. Despite widespread publicity about this in the financial press, the study's results and conclusions are biased by faulty statistical tests. Once the methodology is corrected, the differences in stock market returns under different political parties turn out not to be meaningful. The lessons here extend well beyond the presidential political party effect. Proper research design is essential if we are to reach correct conclusions. <bold>TOPICS:</bold> <ext-link>Security analysis and valuation</ext-link>, <ext-link>exchanges/markets/clearinghouses</ext-link>