Elementary Results on Solutions to the Bellman Equation of Dynamic Programming: Existence, Uniqueness, and Convergence

We establish some elementary results on solutions to the Bellman equation without introducing any topological assumption. Under a small number of conditions, we show that the Bellman equation has a unique solution in a certain set, that this solution is the value function, and that the value function can be computed by value iteration with an appropriate initial condition. We also show that the value function can be computed by the same procedure under alternative conditions. We apply our results to two optimal growth models, one with a discontinuous production function, the other with "roughly increasing" returns.