A long-term objective of all governments is to achieve steady increases in productive capacity. Consequently, economic growth is measured by the rate of change of output. In the United Kingdom a commonly used measure of economic output is GDP: gross (total) domestic (home) product (output). To portray accurately the rate of change of actual output, we must correct GDP for changes in prices. When this is done, we get what is called real GDP. Hence a more formal measure of economic growth may be defined as the rate of change in real GDP over time.