The gold standard is a monetary system in which currencies are defined in terms of a given weight of gold. According to liberal Keynesian economics a gold standard combined with a trade surplus leads to deflation.
The United States used the gold standard until FDR confiscated all private holdings of gold and instituted 'fiat' currency, possibly prolonging the Great Depression. Now, the Federal Reserve can, by federal statute, create money at will. The only limit is the statutory mandate to promote maximum employment, stable prices and moderate interest rates. How much money it creates and what tools it employs to create it are left entirely at the Fed's discretion as it attempts to live up to this impossible set of demands from liberals in Congress. As a result, the growth and contraction of the money supply, economic growth, and inflation have been erratic, contributing to the current Depression.