Gross domestic product
Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced in a period of time, often annually 
GDP (nominal) per capita does not, however, reflect differences in the cost of living and the inflation rates of the countries; therefore using a basis of GDP per capita at purchasing power parity (PPP) is arguably more useful when comparing differences in living standards between nations.
Tendency of the rate of profit to fall
Not only are GDP data frequently revised after first publication, but the popular idea that GDP equals "the whole economy" is a fallacy. It is a fallacy, not just because intermediate items, transfers and net factor income from abroad are excluded, but also because more domestic assets, incomes, transfers and spending exist beyond the defined "production" boundary for Gross Output (including, importantly, activities of government, financial institutions/companies, and households).