Trainers' dilemma of choosing between training and promotion

In the work environment, older employees play a significant role in training younger employees. Why do older employees provide this training when they are rivals competing for promotion? Is it because the more training they provide to trainees, the less likely those trainers will be promoted? We show that the fostering of generalists rather than specialists can soften the trainers' dilemma of choosing between training and promotion because the amount of training provided by a trainer decreases that trainer's promotion probability to a greater extent when training specialists than when training generalists. Hence, even if the productivity of the generalist is lower than that of the specialist, the generalist scheme can still lead to a higher level of training and improve a firm's profit and social welfare.