Classical economics (also known as liberal economics) asserts that markets function best with minimal government interference. It was developed in the late 18th and early 19th century by Adam Smith, Jean-Baptiste Say, David Ricardo, Thomas Robert Malthus, and John Stuart Mill. Many writers found Adam Smith's idea of free markets more convincing than the idea, widely accepted at the time, of protectionism. Many classical economists also believe in a gold standard. and believe that the pervasive use of fiat money explains why classical economics has not worked in the short term.