Girma Sourafel, Paton David
Nottingham University Business School, Nottingham, UK.
Health Econ. 2006 Sep;15(9):1021-32. doi: 10.1002/hec.1129.
In this paper, we demonstrate how matching estimators can be used to evaluate policy interventions which are implemented in relatively few regions at different times. Our technique is based on translating calendar time into 'experimental time' to provide a common starting point for entry by different areas into the scheme. Such an approach is likely to have many applications, in particular to cases of state- or country-level interventions for which only aggregate data are available. We illustrate the technique using the case of free over-the-counter access to emergency birth control for teenagers at pharmacies in England. We construct matching estimates of the impact of this scheme on the under-18 conception rate in local authorities. Irrespective of either the matching or the adjustment procedure, we find no evidence that over-the-counter emergency birth control schemes lead to lower teenage pregnancy rates.
在本文中，我们展示了匹配估计量如何用于评估在不同时间于相对较少地区实施的政策干预措施。我们的技术基于将日历时间转换为“实验时间”，以便为不同地区加入该计划提供一个共同的起始点。这种方法可能有许多应用，特别是对于那些仅有汇总数据可用的州或国家层面的干预措施的情况。我们以英格兰药店向青少年免费提供非处方紧急避孕药的案例来说明该技术。我们构建了该计划对地方当局18岁以下怀孕率影响的匹配估计值。无论采用匹配还是调整程序，我们都没有发现非处方紧急避孕计划会导致青少年怀孕率降低的证据。
