# Why must the wage barganing be derived at steady-state?

In wage bargaining theory, in the context of matching theory, firms and workers can negotiate a Nash equilibrium by maximizing a function of firms' and workers' surplus - with the purpose of allowing voluntary unemployment?. Let's say we have an objective function $N_t$ and we're trying to maximize it with respect to wage rate and hours worked. Why do we insert the steady-state values of the surpluses in $N_t$?

Any help would be appreciated.

• Can you provide the specific setup of the search model you have in mind? – Herr K. Nov 22 '17 at 2:36