... score.13 The CIA assumption is strong because it is based on the assumption that the conditioning variables in X i be sufficientlyrich to justify the application of matching. In particular, CIA requires ... IntroductionWhile marriage remains the most common foundation of family life in the U.S., the prominence of the traditional process of family formation, namely marriage before having children, is diminishing.Today, ... the distribution of the observables in the treated population.14Conditioning on X within a finite sample, however, can be problematic if the vector of observ-ables is of high dimension. The number...