Both human capital accumulation and Lazear contracts can explain the raising wage of salary/wage worker through job experience or tenure. To distinguish between these two effects, Lazear and Moore (1984) used self-employed workers’ wage growth to partial out the effect of human capital...

Previous studies have found that self-employed workers with long business tenure earn less than other workers with similar characteristics. This difference in earnings can be explained by the compensating wage differential theory when self-employed jobs have attractive non-earnings aspects....