Valuing American Options by Simulation : A Simple Least-Squares Approach

This paper presents a simple yet powerful new approach for valuing American options by simulation. The key to this approach is to use least squares to estimate the conditional expected payoff to the optionholder from continuation. This makes this approach readily applicable in path-dependent and multifactor situations where traditional finite difference and binomial techniques cannot be used. We illustrate this technique with a series of realistic examples ranging from the valuation of an American put in a single-factor setting to the valuation of a deferred American swaption in a twenty-factor string model of the term structure