This article specifies and estimates an empirical model of male labor supply based on an implicit market model of wage-hours determination. We discuss how moving from a standard labor supply model to an implicit market model affects model specification and choice of estimation technique. We find that average hourly earnings are not independent of hours worked and that OLS estimates of the wage-hours relationship are biased. We also show that a labor supply model that assumes wages to be independent of hours worked produces a positively biased estimate of the effect of the wage on labor supply.

A wage offer can be either acceptable or unacceptable to a worker, but in cross-sectional and panel data only acceptable wage offers are observed. An OLS wage equation will not reveal how job tenure affects wage offers but rather will reveal how tenure affects acceptable wage offers. By jointly modeling the firm's determination of the wage offer and the worker's decision to accept or reject the offer, we are able to estimate the effect of job tenure on wage offers consistently. In contrast to the usual OLS results, we find that job tenure has no statistically significant effect on wage offers.