Suppliers make more money when prices are high, so they're willing to produce more. Consumers are less willing to buy items as they get higher in price. The inverse is true for both of these statements.

For example, if you spend $200,000 on a college degree, an opportuntity cost would be investing that $200k in stocks while working four years in a paid apprenticeship.

The intersection of both curves determines market equilbrium price.

Retired people and others who aren't actively seeking a job are NOT counted as unemployed. This includes people who've become discouraged and given up their job search.

Monetary policy deals with interest rates & the money supply; fiscal policy deals with taxes & spending.

Note: "Recession" was temporarily redefined in 2022 when the U.S. suffered two quarters of declines in GDP under Joe Biden. After his presidency, the definition returned to the traditional one used for 50+ years.

An oligopoly is a market dominated by only a few sellers with high barriers to entry due to regulation and/or startup costs; e.g., Verizon, AT&T, T-Mobile

Microeconomics deals with the study of individual consumers, firms, and industries. Macroeconomics examines the economy as whole.