Sample Selection Bias as a Specification Error: A Comment

Web based health surveys: Using a Two Step Heckman model to examine their potential for population health analysis

“…Beginning in the late 1970s (Greene, 1981;Heckman, 1976Heckman, , 1978Heckman, , 1979, methods for detecting and statistically correcting selection bias were developed in economics and related areas. In the decades since, as noted by Cuddleback and colleagues (2004), an extensive literature has evolved in the area of sample selection bias (Berk, 1983;Stolzenberg & Relles, 1997).…”

Factors affecting hospital admission and recovery stay duration of in-patient motor victims in Spain

“…OLS standard errors have to be corrected to account for these particularities. An estimator of the asymptotic covariance matrix is provided by Heckman (1979) and Greene (1981). The covariance matrix may also be estimated by means of bootstrapping techniques, as provided by most commercial statistical software.…”

Censored Data and Truncated Distributions

“…There are two methods of estimating this model, two step (not two stage) least squares and maximum likelihood. The two step method was proposed by Heckman (1979) [see also, Greene (1981Greene ( , 2003]. The logic of Heckman's method is strikingly simple.…”