adam smith bernard mandeville classical economics comparative advantage competition corn laws cost-of-production theory of value currency david hume economic rent economics edward gibbon wakefield francis place free trade gatcombe park gloucestershire great britain heckscher-ohlin theorem henry charles carey holland ireland james mill jean-baptiste say jeremy bentham john ramsay mcculloch john stuart mill karl marx labor theory of value life guards london member of parliament nassau william senior on the principles of political economy and taxation oxfordshire parliament of the united kingdom piero sraffa political economy club political economy protectionism religious society of friends ricardian economics ricardian equivalence richard sharp robert barro samuel hollander schools of economic thought the wealth of nations thomas malthus thomas tooke unitarianism value theory wikisource