The effect of college curriculum on earnings: An affinity identifier for non-ignorable non-response bias

We link information on graduates from many cohorts to their high-school and college records and demographics to infer the impact of college major on earnings. We develop an estimator to handle potential non-response bias and identify non-response using an affinity measure--the potential respondent's link to the survey organization. This technique is generally applicable for adjusting for unit non-response. In the earnings model estimated using the identified (for non-response bias) selectivity adjustments, adjusted earnings differentials across college majors are below half as large as unadjusted differentials and ten percent smaller than those that do not account for selective non-response.