The Specification and Power of the Sign Test in Event Study Hypothesis Tests Using Daily Stock Returns
评估了事件研究中用于检测异常股票收益的非参数符号检验，发现其比参数t检验设定更准确、检验力更高，但不如秩检验。
This paper evaluates a nonparametric sign test for abnormal security price performance in event studies. The sign test statistic examined here does not require a symmetrical distribution of security excess returns for correct specification. Sign test performance is compared to a parametric r-test and a nonparametric rank test. Simulations with daily security return data show that the sign test is better specified under the null hypothesis and often more powerful under the alternative hypothesis than a r-test. The performance of the sign test is dominated by the performance of a rank test, however, indicating that the rank test is preferable to the sign test in obtaining nonparametric inferences concerning abnormal security price performance in event studies.