An analytical solution to the lab-equipment growth model (Rivera-Batiz and Romer,1991) with an exogenous imitation rate is presented and applied to study the policy tradeoff between weaker levels of intellectual property rights (IPR) protection yielding more consumption today, and stronger...

Several works in the shopping-time and in the human-capital literature, due to the nonconcavity of the underlying Hamiltonian, use first-order conditions in dynamic optimization to characterize necessity, but not sufficiency, in intertemporal problems. In this work I choose one paper in each one...