Taking negative externalities into account when thinking about the optimal equilibrium price and quantity. Created by Sal Khan.

The market for loanable funds brings savers and borrowers together. We can also represent the same idea using a mathematical model. In this video, learn about the savings and investment identity.

Demand for normal goods increases when income increases, but demand for inferior goods decreases when income increases. In this video, we use the example of a computer and a car to describe the concepts of normal goods and inferior goods and show how a change in income affects the demand for each using a graph of the demand curve. Created by Sal Khan.

Positive statements are fact-based, but normative statements are based on opinions. In this video, learn about the distinction between positive statements and normative statements, and why economists emphasize positive analysis vs. normative analysis, as well as how to identify positive statements vs. normative statements.

Competition runs across a spectrum from perfectly competitive to monopoly, and two types of competition that lie within this spectrum are monopolistic competition and oligopolies. In this video, we briefly compare these two forms of competition. Created by Sal Khan.

When does an oligopoly act more like a perfectly competitive firm, and when does it act more like a monopolist? Find out in this video. Created by Sal Khan.

Opportunity cost is the value of something given up to obtain something else. In this video, we explore the definition of opportunity cost, how to calculate opportunity cost, and how the PPC illustrates opportunity cost. Created by Sal Khan.

In this video, we use the PPCs for two different countries that each produce two goods in order to create an output table based on the data in the graph. We then use the output table to determine the opportunity costs of producing each good. Finally, we determine which country has a comparative advantage in each good.

In this video, we use the PPCs for two different countries that each produce two goods in order to create an output table based on the data in the graph. We then use the output table to determine the opportunity costs of producing each good. Finally, we determine which country has a comparative advantage in each good.

A rational agent considers all costs, including explicit and implicit costs, when deciding whether or not to undertake an action. In this video, learn about how opportunity costs represent the cost of the next best alternative.

Using indifference curves to think about the point on the budget line that maximizes total utility. Created by Sal Khan.

Using some basic calculus to show that marginal revenue has twice the slope of the demand curve for a monopolist. Created by Sal Khan.

Big picture of how money enters circulation and how lending can increase the money supply. Created by Sal Khan.

The shape of a production possibility curve (PPC) reveals important information about the opportunity cost involved in producing two goods. When the PPC is a straight line, opportunity costs are the same no matter how far you move along the curve. When the PPC is concave (bowed out), opportunity costs increase as you move along the curve. When the PPC is convex (bowed in), opportunity costs are decreasing.

In this video, we break down GDP into its components to better understand what's counted in GDP and what's not counted. Created by Sal Khan.

Analysis of how well average inflation-adjusted after-tax income for the bottom 90% has tracked per capital GDP over the past 70 years. Created by Sal Khan.

What would happen if we have a percentage tax instead of a fixed dollar amount. Created by Sal Khan.

The most common forms of competition you learn about in microeconomics are perfect competition, monopolies, oligopoly, monopsony, and monopolistic competition. In this video we briefly describe the key features of each.

Examining the two extremes of elasticity, perfectly elastic and perfectly inelastic demand, can help us beter understand the intuition behind this measure. Created by Sal Khan.

In 1958, economist Bill Phillips described an apparent inverse relationship between unemployment and inflation. Later economists researching this idea dubbed this relationship the "Phillips Curve". Learn about the curve that launched a thousand macroeconomic debates in this video. Created by Sal Khan.