Many empirical studies specify outcomes as a linear function of endogenous regressors when conducting instrumental variable (IV) estimation. We show that tests for treatment effects, selection bias, and treatment effect heterogeneity are biased if the true relationship is non-linear. These...

This study examines the link between divorced nonresident fathers' proximity and children's long-run outcomes using high-quality data from Norwegian population registers. We follow (from birth to young adulthood) 15,992 children born into married households in Norway in the years 1975-1979 whose...

This paper uses a rich Norwegian dataset to re-examine the causal relationship between family income and child outcomes. Motivated by theoretical predictions and OLS results that suggest a nonlinear relationship, we depart from previous studies in allowing the marginal effects on children’s...