We consider an fg model at the deterministic steady state:
\(s = g\left(s, x, \epsilon \right)\)
\(0 = \left[ f\left(s, x, s, x \right) \right]\)
where \(g\) is the state transition function, and \(f\) is the arbitrage equation. Note that the shocks, \(\epsilon\), are held at their deterministic mean.
The steady state function consists in solving the system of arbitrage equations for the steady state values of the controls, \(x\), which can then be used along with the transition function to find the steady state values of the state variables, \(s\).