The classical economists saw the essence of the economic problem as one of producing and distributing the economic wealth created between landowners, labour and capitalists; and were concerned to show how the interplay of separate decisions by workers and capitalists could be harmonized through the market system to generate economic wealth. Their belief in the power of market forces led them to support LAISSEZ-FAIRE, and they also supported the idea of FREE TRADE between nations. After about 1870, classical economic ideas receded as the emphasis shifted to what has become known as NEOCLASSICAL ECONOMIC ANALYSIS, embodying marginalist concepts. Classical economists denied any possibility of UNEMPLOYMENT caused by deficient AGGREGATE DEMAND, arguing that market forces would operate to keep aggregate demand and POTENTIAL GROSS NATIONAL PRODUCT in balance (SAY'S LAW). Specifically they argued that business recessions would cause interest rates to fall under the pressure of accumulating savings, so encouraging businesses to borrow and invest more, and would cause wage rates to fall under the pressure of rising unemployment, so encouraging businessmen to employ more workers. See LABOUR THEORY OF VALUE, KEYNES, PRIVATE ENTERPRISE ECONOMY.