Maintains that the equal marginal value principle may not be optimal in the analysis of the cost-effectiveness of policies to reduce auto emissions, the economics of garbage disposal, and the economics of pollution abatement. Argues that examining these exceptions can help students understand the equal marginal value principle. (MJP)

Describes class exercises where undergraduates construct and test mathematical models using data and issues related to social security. The students collect data and forecast economic and demographic variables that determine future tax rates. They then discuss government policies that are derived from their models. (MJP)