When do firms and unions agree on a monopoly union or an efficient bargaining arrangement?

In this paper we investigate the effects of two popular labour market institutions – namely, Monopoly Union (MU) and Efficient Bargaining (EB) – in a Cournot duopoly, in particular as regards the issue of the bargaining agenda. We show that, while when EB and Right-to- Manage arrangements are considered no agreement on the scope of bargaining may occur, when exogenously given MU and EB arrangements are compared both firms and unions may find more convenient the MU institution. This occurs in particular when the value of the union’s bargaining power is included in a “medium-high” range. However this result is not robust to the endogeneization of the scope of bargaining: indeed in the latter case both firms and unions agree with the choice of the EB arrangement for a sizable range of the union's power. Therefore the detection of a set of union bargaining power values for which there exists an agreement between firms and unions eitheron the MU institution in the case of exogenously given arrang ements or on the EB institution in the case of endogenously determined arrangement may be interesting also for policy purposes.