Summary
Highlights
Life is compared to a giant store where individuals wake up to thousands of goods. The goal is to make oneself as well-off as possible by deciding which goods to buy, which requires considering individual preferences for various quantities and goods. Initially, the concept is explored without budget constraints, imagining a lottery winner who can buy anything.
For a rational consumer, preferences follow specific rules: 1) Completeness: When comparing two bundles, one must prefer one over the other or be indifferent. 2) Transitivity: Preferences must be logically consistent (e.g., if A is preferred to B, and B to C, then A must be preferred to C). 3) Non-satiation: More is always better; consumers will take additional goods even if the marginal satisfaction decreases.
Preferences can be represented graphically using indifference curves, similar to a subway map or an emoji simplifying a mood. An example is given with pizza slices and cookies, where different bundles are considered. The axes of the graph represent the quantities of each good, and points are plotted for different bundles.
An indifference curve connects bundles of goods between which a consumer is indifferent, meaning they provide the same level of satisfaction. A higher indifference curve represents a higher level of satisfaction because it generally means more of both goods are consumed. The example illustrates how a bundle with more of both goods lies on a higher indifference curve.
Four key properties of indifference curves are discussed: 1) Consumers prefer higher indifference curves (more is better). 2) Indifference curves are downward sloping (to get more of one good, some of the other must be given up). 3) Indifference curves never cross. 4) There is one indifference curve through each possible bundle of goods.