MacMillan-CSAP Workshop on Quantitative Research Methods: Cyrus Samii, “From Local to Global: External Validity in a Fertility Natural Experiment”

“From Local to Global: External Validity in a Fertility Natural Experiment” (Joint with Rajeev Dehejia and Cristian Pop-Eleches)

Speaker: Cyrus Samii, Assistant Professor in the Department of Politics, New York University

Abstract: Experimental evidence on a wide range of interventions in development economics is accumulating rapidly. Setting aside questions of internal validity, we ask whether it is possible to reach externally valid conclusions from experimental evidence for other contexts of interests, and which factors (geography, context variables, individual variables) determine the accuracy of such an extrapolation. We use the Angrist and Evans (1998) sex composition natural experiment and data from International IPUMS on 166 country-year censuses to develop and implement a framework for considering questions of external validity for an experimental evidence base. We find significant variation in the effect of sex composition on incremental fertility and find that differences in geography, education, time, and labor force participation between the target and experimental countries are all important predictors of external validity in the expected direction. We develop and apply a framework for deciding whether an evidence base is sufficient for policy decisions or whether further experimentation is necessary.

Bio: Cyrus Samii is Assistant Professor with the Department of Politics, New York University.  He writes and teaches on quantitative social science methodology, with an emphasis on causal inference, and on substantive topics in political economy and development. He holds a PhD from Columbia University and BA from Tufts University.