The relative effectiveness of incentive plans administered on continuous and VR‐4 schedules of reinforcement was investigated with unionized employees using a within subjects design. Mountain beaver trappers working side by side were randomly assigned to one of two groups. In group A the trappers received $1.00 for every rat they trapped. At the end of four weeks, they were switched to a VR‐4 schedule in which they received $4.00 contingent upon trapping a rat and correctly guessing the color of one of four marbles prior to drawing it from a bag held by the supervisor. In group B the order of the schedules was reversed. The results were analyzed in terms of cost‐related, behavioral, and reaction criteria. The study increased employee productivity and decreased costs for the company. Inexperienced workers had higher productivity on the continuous reinforcement than on the VR‐4 schedule; experienced workers had higher productivity on the VR‐4 schedule than on the continuous schedule. Both the experienced and the inexperienced employees preferred the VR‐4 schedule over the continuo