 Economic growth is the increase in the inflation-adjusted market value of the goods and services produced by an economy over time. It is conventionally measured as the percent rate of increase in real gross domestic product, or real GDP. Growth is usually calculated in real terms, i.e., inflation-adjusted terms, to eliminate the distorting effect of inflation on the price of goods produced. Measurement of economic growth uses national income accounting. Since economic growth is measured as the annual percent change of gross domestic product GDP it has all the advantages and drawbacks of that measure. The economic growth rates of nations is commonly compared using the ratio of the GDP to population or per capita income. The rate of economic growth refers to the geometric annual rate of growth in GDP between the first and the last year over a period of time. Implicitly, this growth rate is the trend in the average level of GDP over the period, which implicitly ignores the flood situations in the GDP around this trend. An increase in economic growth caused by more efficient use of inputs such as labor productivity, physical capital, energy or materials is referred to as intensive growth. GDP growth caused only by increases in the amount of inputs available for use. Increased population, new territory is called extensive growth. The rate of new goods and services also creates economic growth.