the analysis of possible further effects of informative asymmetries, most of which are not eliminable in the labour market, and in particular of those that hinder an optimum risk distribution between employer and employee, so justifying the mandatory limitation of the employer’s dismissal power as a second best, in a situation in which the first best (the free and efficient negotiation of the risk distribution between employers and employees) is in fact unattainable (Aghion and Hermalin, 1990).