Imbens, Guido (contributor); … - 2008
effect of the exposure
of a set of units to a program or treatment on some outcome. In economic studies, the units are … of the treatment. An individual may enroll or not in a training program, or he
or she may receive or not receive a … same unit when exposed, and
when not exposed, to the treatment. The problem is that we can at most observe one of these …