This calculation was based on the following formula: production minus exports plus imports plus or minus changes in stocks).

Natural resources in the sense that the accounts should make it possible to describe stocks and changes in stocks of selected finite or renewable resources.

National expenditure, then, is the sum of consumption of domestically produced goods, investment (including changes in stocks and work in progress), government expenditure and exports.

One approach involves increasingly speculative trading operations; the other involves derivatives, which are complicated contracts that allow traders to bet on the direction of future price changes in stocks, bonds, currencies and other financial instruments.

Among the groups considered to be day traders are Wall Street firms investing their own capital, program traders, hedge funds, mutual fund switchers and pension funds using tactical asset allocation, a computer-driven formula based on changes in stocks, bonds and cash.

Analogous to today where wealth can fluctuate with value changes in stocks, factories, and other forms of property, the South suffered a huge loss of total wealth and assets when the American Civil War ended and slaves were no longer counted as physical property.

Note: The sum of "Production" and "Imports" less "Exports" may not equal "Consumption" due to changes in stocks, losses, unaccounted-for coal, and special arrangements such as the United States shipments of anthracite to United States Armed Forces in Europe.