Nonparametric Bounds on the Causal Effect of University Studies on Job Opportunities Using Principal Stratification

The authors propose a methodology based on the principal strata approach to causal inference for assessing the relative effectiveness of two degree programs with respect to the employment status of their graduates. An innovative use of nonparametric bounds in the principal strata framework is shown, examining the role of some assumptions in reducing uncertainty about the causal effects and proposing a strategy to use the covariates in the construction of the bounds. In the application, the nonparametric bounds turn out to be quite informative on the average causal effect for the latent group of students who are potentially able to graduate from both degree programs. There is some evidence that the effect is positive for economics with respect to political science, at least for some values of the covariates.