A firm in a perfectly competitive market might be able to earn economic profit in the short run, but not in the long run. Learn about the process that brings a firm to normal economic profits in this video.

A demand shock has a short-run effect on an output and unemployment, but in the long run only the price level will be impacted. If there is an increase in aggregate demand, the price level will go up. Once wages have adjusted to that inflation in the long run, SRAS decreases and returns the economy to full employment output. Shocks do not cause economic growth, only changes in full employment output cause economic growth.

A constant cost industry is an industry where each firm's costs aren't impacted by the entry or exit of new firms. Learn about the difference between the short run market supply curve and the long run market supply curve for perfectly competitive firms in constant cost industries in this video.

In some industries, the number of firms in the market has an impact on the costs that firms face. For example, when firms have to compete with each other over resources, firms' costs increase as more firms enter the market. But in other industries, more firms actually lower costs for firms. Learn about the implications of each of these situations on the long-run supply curve in an industry.

In a long straddle you benefit from large price movements. In this video we explore what a straddle is with options and see an example of a long straddle. Created by Sal Khan.

Understanding the long term supply curve in terms of economic profit. Created by Sal Khan.

Leveraging a diagram from the New York Times to look at trends in inflation adjusted income since 1980. Discussion of possible levers that could be driving the trends. Created by Sal Khan.

The expenditure and tax multipliers depend on how much people spend out of an additional dollar of income, which is called the marginal propensity to consume (MPC). In this video, explore the intuition behind the MPC and how to use the MPC to calculate the expenditure multiplier. Created by Sal Khan.

See how a wire carrying a current creates a magnetic field. Created by Sal Khan.

Sal shows how to determine the magnetic force between two currents going in opposite directions. Created by Sal Khan.

Sal shows how to determine the magnetic force between two currents going in the same direction. Created by Sal Khan.

Sal shows how to find the size and direction of the magnetic force using F=qvB and the right hand rule. Created by Sal Khan.

Sal derives the formula F=ILB to determine the force on a current carrying wire. Created by Sal Khan.

Sal does an example problem to determine the size and direction of the magnetic force on a proton moving through a magnetic field. Created by Sal Khan.

Sal determines the radius of the circle traveled by the proton in the previous example by using the formula for centripetal acceleration. Created by Sal Khan.

Once you've found your dream home, you have to make an offer on it. In this video learn how making an offer on a house works and the various steps and pitfalls in that process.

In this video we calculate the costs of producing a good, including fixed costs, variable costs, marginal cost, average variable cost, average fixed cost, and average total cost.

Given the cost of producing a good, what is the best quantity to produce? In this video we explore one of the most fundamental rules in microeconomics: a rational producer produces the quantity where marginal revenue equals marginal costs. Created by Sal Khan.

This video discusses the differences in a graph of marginal cost and marginal revenue for an imperfectly competitive firm compared to a perfectly competitive firm.