We apply numerical dynamic programming to multi-asset dynamic portfolio optimization problems with proportional transaction costs. Examples include problems with one safe asset plus two to six risky stocks, and seven to 360 trading periods in a finite horizon problem. These examples show that it...

We model welfare-maximizing policy in an infinite-horizon setting when the probability of a tipping point, the welfare change due to a tipping point, and knowledge about a tipping point's trigger all depend on the policy path. Analytic results demonstrate how optimal policy depends on the...

We introduce an algorithm for solving dynamic economic models that merges stochastic simulation and projection approaches: we use simulation to approximate the ergodic measure of the solution, we construct a fixed grid covering the support of the constructed ergodic measure, and we use...

Linear RE models typically possess a multiplicity of solutions. Consider, however, the requirement that the solution coefficients must not be infinitely discontinuous in the model's structural parameters. In particular, we require that the solutions should be continuous in the limit as those...

Continuous time is a superior representation of both the economic and climate systems that Integrated Assessment Models (IAM) aim to study. Moreover, continuous-time representations are simple to express. Continuous-time models are usually solved by discretizing time, but the quality of a...

The absence of self-control is often viewed as an important correlate of persistent poverty. Using a standard intertemporal allocation problem with credit constraints faced by an individual with quasi- hyperbolic preferences, we argue that poverty damages the ability to exercise self-control....

Numerical dynamic programming algorithms typically use Lagrange data to approximate value functions over continuous states. Hermite data is easily obtained from solving the Bellman equation and can be used to approximate value functions. We illustrate this method with one-, three-, and...

An enhanced version of a structural model jointly explains benefit claiming, wealth and retirement, including reversals from states of lesser to greater work. The model includes stochastic returns on assets. Estimated with Health and Retirement Study data, it does a better job of predicting...

We consider infinite horizon economies populated by a continuum of agents who are subject to idiosyncratic shocks. This framework contains models of saving and capital accumulation with incomplete markets in the spirit of works by Bewley, Aiyagari, and Huggett, and models of entry, exit and...

We implement a dynamic programming algorithm on a computational grid consisting of loosely coupled processors, possibly including clusters and individual workstations. The grid changes dynamically during the computation, as processors enter and leave the pool of workstations. The algorithm is...