Reviews economic models, especially treatment of competition, marketing practices, and international trade effects on U.S. cattle prices and producers' incomes. The report addresses 3 questions: To what extent do these models incorporate structural changes -- specifically, market concentration in the meatpacking sector and the use of marketing agreements, forward contracts, and imports?; What are the most important factors that affect cattle prices and producers' incomes?; and What are the most significant data and modeling issues to be considered in developing a more comprehensive model, or logical framework, to explain cattle prices and producers' income? Makes recommendations about how to resolve issues and problems regarding cattle price modeling.