Becker, Sascha and Andrea Ichino (2002), “Estimation of average treatment effects based on propensity score”, The Stata Journal, Vol. 2, No. 4, pp. 358-377.

在研究treatment effect的时候，treatment group 和controle group之间，可能由于self-selection等原因存在差异的。一个解决的办法是通过propensity score配比样本。

[此贴子已经被作者于2007-8-7 23:42:36编辑过]