External certification of workplace skills obtained through on-the-job training is widespread in many countries. This may indicate that training is financed by workers, and certification serves to assure the quality of the training offered by the firm. However, other evidence shows that general...

In the human capital model with perfect labor markets, firms never invest in general skills and all costs of general training are borne by workers. When labor market frictions compress the structure of wages, firms may pay for these investments. The distortion in the wage structure turns...