Earnings non response in the Current Population Survey is roughly 30% in the monthly surveys and 20% in the annual March survey. Even if non response is random, severe bias
attaches to wage equation coefficient estimates on attributes not matched in the earnings imputation hot deck. If non response is ignorable, unbiased estimates can be achieved by omitting imputed earners, yet little is known about whether or not CPS non response is ignorable. Using sample frame measures to identify selection, we find clear-cut evidence among men but limited evidence among women for negative selection into response. Wage equation slope coefficients are affected little by selection but because of intercept shifts, wages for men and to a lesser extent women are understated, as are gender wage gaps.
Selection is less severe among household heads/co-heads than among other household members.