14.2 Dynamic Economic Models Autoregressive and Distributed Lag models ■1。 Definition Dynamic models/ Distributed lag models There is a non-contemporaneous, or lagged, relationship between Y and the x for the effect of a unit change in the value of the explanatory variable is spread over. or distributed over. a number of time periods14.2 Dynamic Economic Models: Autoregressive and Distributed Lag Models ◼ 1. Definition Dynamic models/ Distributed lag models: －－There is a non-contemporaneous, or lagged, relationship between Y and the Xs , for the effect of a unit change in the value of the explanatory variable is spread over, or distributed over, a number of time periods