The standard efficient contract involving a monopolistic firm and a union has always been derived under the assumption that the firm operates efficiently, i.e. it uses fully its labor force. However, nothing constrains the firm to do so and production with under-utilization of labor may actually...

The usual 'efficient' bargaining solution between a monopolistic firm and a union has always been derived under the constraint that the firm produces on its production frontier. The authors show that, if the union is risk-averse and powerful enough, this constrained efficient bargaining solution...