Editing Economic growth (section)

=== Importance of long-run growth ===
Over long periods of time, even small rates of [[exponential growth|growth]], such as a 2% annual increase, have large effects. For example, the United Kingdom experienced a 1.97% average annual increase in its inflation-adjusted GDP between 1830 and 2008.<ref>{{cite web |author1=Ryland Thomas |author2=Samuel H. Williamson |title=What Was the U.K. GDP Then? |website=MeasuringWorth |year=2022 |url=http://www.measuringworth.com/ukgdp/}}</ref> In 1830, the GDP was 41,373 million pounds. It grew to 1,330,088 million pounds by 2008. A growth rate that averaged 1.97% over 178 years resulted in a 32-fold increase in GDP by 2008.

The large impact of a relatively small growth rate over a long period of time is due to the power of [[exponential growth]]. The [[rule of 72]], a mathematical result, states that if something grows at the rate of x% per year, then its level will double every 72/x years. For example, a growth rate of 2.5% per annum leads to a doubling of the GDP within 28.8 years, whilst a growth rate of 8% per year leads to a doubling of GDP within nine years. Thus, a small difference in economic growth rates between countries can result in very different standards of living for their populations if this small difference continues for many years.