* is determined also by other factors such as money, the ERU need not be constant. Even when u = ERU[REH] for each separate year, then

might still have an erratic development over the years. Similarly, the CWIRU can be an ERU[REH], but need not be. It can even be that

= E[

] but expectations are not REH - since the error is not white noise.

For full employment, policy is successful, if and only if u = uf and

=