ABNORMAL SELECTION BIAS

Publisher Summary This chapter discusses abnormal selection bias. The normal selection-bias adjustment procedure can be sensitive to modest departures from normality. The chapter describes the properties of the normal-adjusted estimators when the disturbance distribution is not bivariate normal. The asymptotic bias of the normal-adjusted estimator, as a function of θ, is the truncation point, which is expressed as a deviation from the true population mean. The chapter discusses some general properties of truncated mean functions. The normal selection-bias adjustment procedure will be quite sensitive to modest departures from normality. Consequently, a more general functional form of the truncated mean functions might be required in practice.