Counter intuitive results in a simple model of wage negotiations

Short-term contracts and exogenous productivity growth are introduced in a simple wage bargaining model. The equilibrium utilities corresponding to militant union behaviour are independent of the contract length. Necessary and sufficient conditions for monotonic convergence to a unique steady state are derived. Otherwise, cyclic behaviour of wage shares is inevitable. A wage decrease can occur if strike is credible, but never when strike is not credible. In the limit, as time between bargaining rounds vanishes, this paradox survives.