The Great Depression, which began with the collapse of the New York Stock Exchange in 1929, was the most severe, prolonged, and widespread recession in history. Economists attribute the crisis to a fall in confidence, suggesting massive government interventions to address it. Monetarists criticize the Federal Reserve's action, which, according to them, implemented restrictive monetary policies. Other theories include institutional reasons, a speculative bubble according to the Austrian school, and social inequality as an excess supply. The gold standard, an international exchange regime, accelerated the spread of the recession. The abandonment of this system anticipated recovery. The United States experienced a massive economic contraction, with industrial production decreased by 45%, an unemployment rate of 25%, and international trade reduced by 60%. The recovery, which began around 1933, was attributed to Roosevelt's New Deal.