Final answer:
GDP is calculated by summing consumption, investment, government spending, and net exports, and it only includes production within a country's borders, unlike GNP which also factors in domestic production abroad.
Step-by-step explanation:
The gross domestic product (GDP) of a country can be found by summing consumption, investment, government spending and net exports. It is important to differentiate between GDP and gross national product (GNP). While GDP includes only the production within a country's borders, GNP adds the output from domestic businesses and labor abroad and subtracts the outflow of income to foreign labor and businesses in the home country. Hence, GDP does not include output produced by a country's citizens living abroad, and it is not necessarily equal to GNP. In some cases, especially for smaller nations with significant populations working overseas, GDP can indeed be less than GNP. However, for larger economies like the United States, the difference between GDP and GNP is typically small (recently around 0.2%).