TY - JOUR A1 - Kalwij, Adriaan T1 - An empirical analysis of the importance of controlling for unobserved heterogeneity when estimating the income-mortality gradient Y1 - 2014/10/17 JF - Demographic Research JO - Demographic Research SN - 1435-9871 SP - 913 EP - 940 DO - 10.4054/DemRes.2014.31.30 VL - 31 IS - 30 UR - https://www.demographic-research.org/volumes/vol31/30/ L1 - https://www.demographic-research.org/volumes/vol31/30/31-30.pdf L2 - https://www.demographic-research.org/volumes/vol31/30/31-30.pdf N2 - Background: Statistical theory predicts that failing to control for unobserved heterogeneity in a Gompertz mortality risk model attenuates the estimated income-mortality gradient toward zero. Objective: I assess the empirical importance of controlling for unobserved heterogeneity in a Gompertz mortality risk model when estimating the income-mortality gradient. The analysis is carried out using individual-level administrative data from the Netherlands over the period 1996-2012. Methods: I estimate a Gompertz mortality risk model in which unobserved heterogeneity has a gamma distribution and left-truncation of life durations is explicitly taken into account. Results: I find that, despite a strong and significant presence of unobserved heterogeneity in both the male and female samples, failure to control for unobserved heterogeneity yields only a small and insignificant attenuation bias in the negative income-mortality gradient. Conclusions: The main finding, a small and insignificant attenuation bias in the negative income-mortality gradient when failing to control for unobserved heterogeneity, is positive news for the many empirical studies, whose estimations of the income-mortality gradient ignore unobserved heterogeneity. ER -