Stock And Flow
Economics, business, accounting, and related fields often distinguish between quantities that are stocks and those that are flows. These differ in their units of measurement. A stock variable is measured at one specific time, and represents a quantity existing at that point in time (say, December 31, 2004), which may have accumulated in the past. A flow variable is measured over an interval of time. Therefore a flow would be measured per unit of time (say a year). Flow is roughly analogous to rate or speed in this sense.
For example, U.S. nominal gross domestic product refers to a total number of dollars spent over a time period, such as a year. Therefore it is a flow variable, and has units of dollars/year. In contrast, the U.S. nominal capital stock is the total value, in dollars, of equipment, buildings, inventories, and other real assets in the U.S. economy, and has units of dollars. The diagram provides an intuitive illustration of how the stock of capital currently available is increased by the flow of new investment and depleted by the flow of depreciation.
Read more about Stock And Flow: Stocks and Flows in Accounting, Comparing Stocks and Flows, More General Uses, Calculus Interpretation, Example of Dynamic Stock and Flow Diagram, History
Famous quotes containing the words stock and, stock and/or flow:
“Death and life were not
Till man made up the whole,
Made lock, stock and barrel
Out of his bitter soul,”
—William Butler Yeats (1865–1939)
“All that stock of arguments [the skeptics] produce to depreciate our faculties, and make mankind appear ignorant and low, are drawn principally from this head, to wit, that we are under an invincible blindness as to the true and real nature of things.”
—George Berkeley (1685–1753)
“Parents ought, through their own behavior and the values by which they live, to provide direction for their children. But they need to rid themselves of the idea that there are surefire methods which, when well applied, will produce certain predictable results. Whatever we do with and for our children ought to flow from our understanding of and our feelings for the particular situation and the relation we wish to exist between us and our child.”
—Bruno Bettelheim (20th century)