Supplement to "Collusion with Persistent Cost Shocks"

This document has three parts.  The first part analyzes generalizations of our model to downward-sloping demand, imperfect substitutes, Cournot competition, and nonlinear cost functions.  The second part describes a general dynamic programming approach to games with serially correlated private information.  The third part establishes conditions for the existence of an equilibrium with productive efficiency for perfectly persistent types, and also includes an analysis of severe "belief threat" punishments.

Supplemental Authors: 
Susan Athey and Kyle Bagwell