Question

Many countries, including the United States, measure output by calculating the _____.

Answer 1

Answer is Gross Domestic Product.

Gross domestic product (GDP) is the total value of all finished goods and services produced in a country's in a particular time frame. Though GDP is usually calculated on an annual basis, it can be calculated on a quarterly basis. For example, in the United States, the government releases an annualized GDP estimate for each quarter and also for an entire year. GDP indicates the economic health of a country. It is used to gauge standard of living of a country.

Answer 2

These countries, together with the United States of America measure output through the calculation of complex indexes and metrices which, when taken together, are known as the Gross Domestic Product (GDP). 

Both the economic peaks and cycles refer to other things, which are mildly related to the gross domestic product.