In this chapter we present a number of models in resources and environmental economics in which economic agents (firms or countries) exploit natural resources or the environment in an intertemporal context, taking into account the strategic behaviour of other agents.

We begin with a simple model of exploitation of a common-property, nonrenewable resource such as an oil field. We compare the benchmark cooperative solution with a noncooperative open-loop Nash equilibrium and a Markov perfect Nash equilibrium. In the open-loop version of the game, we show that the nature of the solution depends on how we restrict the set of feasible strategies available to each agent. This is an important issue from the modelling point of view, especially in the context of common property resources, because this context dramatically highlights the interdependence among agents, not only in terms of payoffs but also in terms of what one agent can do given the actions of others.

After a thorough discussion, we consider some variations of the basic model of common-property nonrenewable resources: the so-called doomsday problem, and the problem where utility depends directly on both the stock of the resource and the flow of consumption.

Renewable resources such as fish stocks and forests are considered next, at first in the standard format of simultaneous choice of Markovian strategies. The game is then modified to allow for history-dependent strategies (such as trigger strategies), and for hierarchical moves, thus illustrating a Stackelberg leadership formulation of a fishery game.