In an optimal growth model with a time-to-build delay, the feasibility condition is a delayed-differential equation, and the Euler-type condition is an advanced-differential equation. As in Kalecki's theory of business cycles, the delayed nature of the feasibility constraint naturally induces...

Differential equations with advanced and delayed time arguments may arise in the optimality conditions of simple growth models with delays. Models with investment gestation lags (time-to-build), consumption gestation lags (habit formation) or learning by using lie in this category. In this...