In this paper we study the behavior of optimal paths in dynamic programming
models with a strictly convex return function. Such a model has been inves
tigated in Dawid and Kopel (1997) who assume that the growth of a renewable
resource is governed by a piecewise linear function. We prove that in thei
r model the optimal cycles undergo the following qualitative changes or bif
urcations: a cycle of period n "bifurcates" into a cycle of period n + 1 fo
r increasing elasticity of the return function. We also show that under the
assumption of a concave differentiable growth function the qualitative pro
perties of the optimal policy remain valid: oscillating behavior is optimal
. Furthermore, we demonstrate numerically that the period of a cyclic optim
al path increases if the convexity of the return function (measured by the
elasticity) increases.