Optimality conditions for age-structured control systems ✩

We consider a fairly general model (extension of the Gurtin–MacCamy model of population dynamics) of an age structured control system with nonlocal dynamics and nonlocal boundary conditions. A necessary optimality condition is obtained in the form of Pontryagin’s maximum principle, which is applicable to a number of practically meaningful models where the previously known results fail.We discuss such models (an epidemic control, and a capital accumulation model) as illustrations.  2003 Elsevier Inc. All rights reserved.