|GDP = private consumption + gross investment + government spending + (exports − imports)|
GDP = C + I + G + (E - M)
Black and gray market transactions don't look like they would be included. Nor are lots of service efforts or new houses.
GDP excludes the income from American owned production that is outside of the USA, but it does include production inside the US even if it is owned by foriegners (like a Japanese car manufacturer in Tennessee). (GNP on the other hand measure everything produced that is American owned, even if it is offshore).
I've always hated the GDP because it treats government spending as production!
C (consumption) is normally the largest GDP component in the economy, consisting of private (household final consumption expenditure) in the economy. These personal expenditures fall under one of the following categories: durable goods, non-durable goods, and services. Examples include food, rent, jewelry, gasoline, and medical expenses but does not include the purchase of new housing.
I (investment) includes, for instance, business investment in equipment, but does not include exchanges of existing assets. Examples include construction of a new mine, purchase of software, or purchase of machinery and equipment for a factory. Spending by households (not government) on new houses is also included in Investment. In contrast to its colloquial meaning, 'Investment' in GDP does not mean purchases of financial products. Buying financial products is classed as 'saving', as opposed to investment. This avoids double-counting: if one buys shares in a company, and the company uses the money received to buy plant, equipment, etc., the amount will be counted toward GDP when the company spends the money on those things; to also count it when one gives it to the company would be to count two times an amount that only corresponds to one group of products. Buying bonds or stocks is a swapping of deeds, a transfer of claims on future production, not directly an expenditure on products.
G (government spending) is the sum of government expenditures on final goods and services. It includes salaries of public servants, purchase of weapons for the military, and any investment expenditure by a government. It does not include any transfer payments, such as social security or unemployment benefits.
X (exports) represents gross exports. GDP captures the amount a country produces, including goods and services produced for other nations' consumption, therefore exports are added.
M (imports) represents gross imports. Imports are subtracted since imported goods will be included in the terms G, I, or C, and must be deducted to avoid counting foreign supply as domestic.
Also from Wikipedia: Austrian School economist Frank Shostak has argued that GDP is an empty abstraction devoid of any link to the real world, and, therefore, has little or no value in economic analysis. Says Shostak:
The GDP framework cannot tell us whether final goods and services that were produced during a particular period of time are a reflection of real wealth expansion, or a reflection of capital consumption. For instance, if a government embarks on the building of a pyramid, which adds absolutely nothing to the well-being of individuals, the GDP framework will regard this as economic growth. In reality, however, the building of the pyramid will divert real funding from wealth-generating activities, thereby stifling the production of wealth.
So what are we to make out of the periodical pronouncements that the economy, as depicted by real GDP, grew by a particular percentage? All we can say is that this percentage has nothing to do with real economic growth and that it most likely mirrors the pace of monetary pumping. We can thus conclude that the GDP framework is an empty abstraction devoid of any link to the real world.