This JiTT exercise uses a real-life example to pose a question to students about the nature of "rationality" as typically used in economics. In this case, the focus is on fixed vs. marginal costs and the use of marginal analysis by economists to make "rational" economic decisions.

In this problem, students consider the benefits of reduced tray usage in school cafeterias by comparing the cost savings of having to clean fewer trays against the opportunity cost of increased labor and energy costs to clean the cafeteria after meals.

Principles of Macroeconomics 2e covers the scope and sequence of most introductory economics courses. The text includes many current examples, which are handled in a politically equitable way. The outcome is a balanced approach to the theory and application of economics concepts. The second edition has been thoroughly revised to increase clarity, update data and current event impacts, and incorporate the feedback from many reviewers and adopters. Changes made in Principles of Macroeconomics 2e are described in the preface and the transition guide to help instructors transition to the second edition. The first edition of Principles of Macroeconomics by OpenStax is available in web view here.

By the end of this section, you will be able to:

Calculate and graph budget constraints
Explain opportunity sets and opportunity costs
Evaluate the law of diminishing marginal utility
Explain how marginal analysis and utility influence choices

This is a clip from Seinfeld in which Jerry does a cost -benefit analysis of installing illegal cable. He decides to commit the crime when he finds out there will be 75 televised Mets games on TV.

This is an excellent clip from The Simpsons that demonstrates the concept of diminishing marginal utility and marginal analysis.

Introduction to economics using notes and a corresponding video teaches students the basic definition of economics which involves individual choice. [1:12]