The unbearable lightness of equilibria in a low interest rate environment

Structural models with no solution are incoherent, and those multiple solutions incomplete. We show that occasionally binding constraints not generically coherent. Coherency requires restrictions on the parameters or support of distribution shocks. In presence shocks, cannot be independent from each other, so assumption orthogonality structural shocks is incompatible coherency. Models whose coherency based incomplete, admitting a very large number minimum state variable solutions.