The orthodox theory of wage negotiations considers that the trade union monopoly causes a rigidity of real wages which is, itself, the cause of unemployment. The model of this negotiation ("Nash bargaining") only considers situations where negotiations between union and firm succeed. In this article, we attempt to read the WS-PS model from a Keynesian point of view. Our model reflects the fact that successful negotiation is only one case among other situations, including failure where the union expresses a claim that is not necessarily satisfied. Although, in situations close to full employment, there is a bargaining mechanism by which unions and firms reach an agreement, this is not the case in times of massive unemployment. In the latter situation, employment is unilaterally determined by firms, on the basis of previous demand.

正统的工资谈判理论认为，工会垄断会导致实际工资的僵化，这本身就是造成失业的原因。这种谈判的模式（“纳什讨价还价”）仅考虑工会与公司之间的谈判成功的情况。在本文中，我们尝试从凯恩斯主义的角度阅读WS-PS模型。我们的模型反映了这样一个事实，即成功的谈判只是其他情况中的一种情况，包括工会表示不一定满足要求的失败。尽管在接近充分就业的情况下，存在工会和公司达成协议的讨价还价机制，但在大规模失业时期却不是这样。在后一种情况下，就业是由公司根据先前的需求单方面确定的。