How fragile are male labor supply function estimates?

We estimate male wage and nonwage income effects using linear specifications spanning three techniques (ordinary least squares, fixed effects, and random effects), two wage measures (reported hourly wages and average hourly earnings), and sample stratification by pay scheme (salaried versus hourly paid). Our regressions encompass the one-period static and perfect-foresight life-cycle models. The static model implies exogenous random person-specific effects, a negative nonwage income coefficient, and a positive labor supply substitution effect. The life-cycle model implies endogenous individual-specific effects, a positive wage coefficient, and a zero nonwage income coefficient. Neither the one-period static nor the perfect-foresight life-cycle models are implied by the data for salaried workers while the static model is consistent with the data for hourly paid workers if income taxes are ignored.