Final answer:
Economists measure output with the gross domestic product (GDP), which is the market value of all final goods and services produced in a country over a specific time period.
Step-by-step explanation:
Economists measure output with the gross domestic product (GDP), which is the market value of all final goods and services produced in a country over a specific time period. GDP measures the actual, tangible goods that are produced and sold in the economy. It uses market prices to calculate the value of these goods and services.