%0 Report %A Heckman, James J. %A Todd, Petra E. %T A Note on Adapting Propensity Score Matching and Selection Models to Choice Based Samples %D 2009 %8 2009 Jul %I Institute of Labor Economics (IZA) %C Bonn %7 IZA Discussion Paper %N 4304 %U https://www.iza.org/index.php/publications/dp4304 %X The probability of selection into treatment plays an important role in matching and selection models. However, this probability can often not be consistently estimated, because of choice-based sampling designs with unknown sampling weights. This note establishes that the selection and matching procedures can be implemented using propensity scores fit on choice-based samples with misspecified weights, because the odds ratio of the propensity score fit on the choice-based sample is monotonically related to the odds ratio of the true propensity scores. %K propensity scores %K matching models %K choice-based sampling %K selection models