mechanism may differ among the levels of nonresponse, and merging the levels of nonresponse may cause bias in the results of the …

relationships among variables as if samples had been collected via random sampling, simplifying bias correction of endogenously …Unlike random sampling, selective sampling draws units based on the outcome values, such as over-sampling rare events … research, such endogenously selected samples must be carefully analyzed to avoid selection bias. We introduce a unified and …

considered and re-estimated using a bivariate selectivity model. Our analysis suggests that sample selection bias could … sample selectivity. But the results obtained by Barro and Mauro are robust to sample selection bias …

bias. We study this by using a data set that combines survey information of individual workers with administrative records … survey respondents and non-respondents. We develop a method to distinguish empirically between two explanations for a bias in … both explanations. We discuss implications for standard methods to deal with non-response bias. …