In economics, marginal cost is the change in the total cost that arises when the quantity produced is incremented by one unit. That is, it is the cost of producing one more unit of a good.In general terms, marginal cost at each level of production includes any additional costs required to produce the next unit.hat is, it is the cost of producing one more unit of a good. In general terms, marginal cost at each level of production includes any additional costs required to produce the next unit.
Economic expansion. An economic expansion is an increase in the level of economic activity, and of the goods and services available. It is a period of economic growth as measured by a rise in real GDP. The explanation of such fluctuations in aggregate economic activity is one of the primary concerns of macroeconomics. Typically an economic expansion is marked by an upturn in production and utilization of resources. Economic recovery and prosperity are two successive phases of expansion.
The economic growth rate provides insight into the general direction and magnitude of growth for the overall economy. In the United States, for example, the long-term economic growth rate is around 2 to 5%. Lower economic growth rates are seen in most highly industrialized countries. Fast-growing economies, on the other hand, see rates as high as 10% although this rate of growth is not likely to be sustainable over the long term.