The Effects of Gain Sharing on the Basic Wage: The Case of IMPROSHARE

Although gain‐sharing plans are typically promoted to workers as a way of increasing total compensation, workers are often concerned that gain‐sharing bonuses may become substitutes for future wage increases that would have occurred in the absence of the plan. I examine the theoretical and empirical interaction among wages, bonuses, effort, and productivity in firms that implemented IMPROSHARE, a well‐known gain‐sharing plan. Using longitudinal data obtained from a detailed survey questionnaire, I find that one can usually reject both the perfectly competitive model in which effort is held constant (in which case bonuses are a perfect substitute for wages) and the “pure gravy” model (in which bonuses completely complement the wage rate). There is no evidence that higher bonuses lead to higher relative wages. The results, however, are not very robust. Although the net effect of the bonuses on the wage rate is usually negative, it is not always statistically significant.