The use of iterative algorithms, based on the Gauss-Seidel method or a similar approach, to solve systems of nonlinear simultaneous equations may lead to problematical situations which in theory are not surprising, but in practice are unexpected by the user. In particular, such situations may arise in the solution of econometric models for simulation purposes. One source of the problem lies in the failure of these algorithms, which repeatedly solve single equations according to some sequential ordering,1 to deal with the interaction properties of specific higher-order subsystems of closely related equations. One illustration of such a subsystem is the set of equations which determines unemployment and labor force in the Wharton Econometric Forecasting Model [1].