The Great Depression was a severe worldwide economic depression in the 1930s. The timing of the Great Depression varied across nations; however, in most countries it started in 1929 and lasted until the late 1930s. It was the longest, deepest, and most widespread depression of the 20th century.Worldwide GDP fell by 15% from 1929 to 1932. In the 21st century, the Great Depression is commonly used as an example of how far the world's economy can decline.