标题：Two-Stage Least Squares Estimation of Average Causal Effects in Models with Variable Treatment Intensity

作者：Joshua D. Angrist and Guido W. Imbens

出版社：Journal of the American Statistical Association, Vol. 90, No. 430 (Jun., 1995), pp. 431-442

电子链接：http://www.jstor.org/pss/2291054

[此贴子已经被作者于2009-5-2 14:36:54编辑过]