Stability and Speed of Adjustment under Retiming of Lags
Donald V. T. Bear
The subject is retiming of lags in a system of linear difference equations. The issues are (i) the effect of lag retiming on stability and (ii) the effect of lag retiming on speed of adjustment. Regarding (i), a theorem due to Bear  is sharpened; and new conditions for stability to survive under a retiming of lags are obtained. Regarding (ii), the main results concern the effects of "lag perturbations" and "spread perturbations" on speed of adjustment in models with nonnegative coefficients.