This document summarizes key concepts from Chapter 5 of the textbook "Principles of Economics, 6th edition" by Karl Case and Ray Fair. It discusses household behavior and consumer choice. Specifically, it covers how households make decisions about demand for goods, labor supply, and savings. It introduces the concepts of budget constraints, opportunity costs, utility, and the utility-maximizing rule for consumers to allocate expenditures between goods in a way that equalizes marginal utility per dollar spent. Diminishing marginal utility and its impact on total utility is also summarized.