Our study considers the question of training in firms using an experimental laboratory approach. We investigate the following questions : What conditions, excluding external certification, will bring workers and employers to cooperate and share a rent generated by the workers' training? What conditions will induce workers to accept the training offer, for employers to initially offer the training and to reward the trained workers in the last stage of the game? We analyse the impact of the size of the rent created by training and the existence of an information system on employer reputation rewarding trained employees. Reputation does matter to induce cooperation, but in the absence of external institutions, coordination on the optimal outcome remains difficult.