What is Gross Domestic Product (GDP)? The definition is rather straightforward: GDP is the market value of all finished goods and services, produced within a country in a year. But that’s not very useful in trying to understand the concept.

In this video by Marginal Revolution University, they mend thinking ofthe economy as a giant supermarket, with billions of goods and services inside. At the checkout line, you watch as the cashier rings up the price for each finished good or service sold. What have you just observed?