This view was challenged in the 1930s during the Great Depression. Keynesian economists argued that the economic system was not self-correcting with respect to deflation and that governments and central banks had to take active measures to boost demand through tax cuts or increases in government spending. Reserve requirements from the central bank were high compared to recent times. So were it not for redemption of currency for gold (in accordance with the gold standard), the central bank could have effectively increased money supply by simply reducing the reserve requirements and through open market operations (e.g., buying treasury bonds for cash) to offset the reduction of money supply in the private sectors due to the collapse of credit (credit is a form of money).