The estudy command proposed by Pacicco, Vena, and Venegoni (2018, Stata Journal 18: 461–476) performs event studies only for event-date clustering, that is, when the event date is common to all securities. This constitutes a relevant limitation because the vast majority of this methodology’s applications concerns studies in which the events happen on different dates for each statistical unit considered. In this article, we propose and describe a substantial update to estudy, which 1) performs event studies in the absence of event-date clustering (that is, when each security has its own event date); 2) further customizes the output by producing L^AT_EX-formatted tables; 3) graphs the cumulative abnormal returns over a customized period set by the user; 4) makes more output data available through either the return list or Excel files; 5) allows a double possibility as input: either prices or returns; and 6) uses wildcards.

由Pacicco，Vena和Venegoni提出的研究命令（2018，Stata Journal 18：461–476 ）仅对事件日期聚类（即，所有证券共有事件日期）执行事件研究。这构成了一个相关的局限性，因为该方法论的绝大多数应用都涉及研究，在这些研究中，事件针对所考虑的每个统计单位都在不同的日期发生。在本文中，我们提议并描述estudy的实质性更新，该更新是：1）在没有事件日期聚类的情况下（即，每个安全性都有其自己的事件日期）执行事件研究；2）通过产生L ^A T _E进一步定制输出X格式的表格；3）绘制用户设置的自定义时段内的累积异常收益；4）通过返回列表或Excel文件提供更多输出数据；5）允许有双重可能性作为输入：价格或收益；和6）使用通配符。