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.
The effect of job tenure on wage offers
Marshall, R. C., & Zarkin, G. A. (1987). The effect of job tenure on wage offers. Journal of Labor Economics, 5(3), 301-324. https://doi.org/10.1086/298149