<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2010) (Learn how and when to remove this template message) </Td> </Tr> <Table> <Tr> <Th> Economics </Th> </Tr> <Tr> <Td> A supply and demand diagram, illustrating the effects of an increase in demand . </Td> </Tr> <Tr> <Td> <Ul> <Li> Index </Li> <Li> Outline </Li> <Li> </Li> </Ul> </Td> </Tr> <Tr> <Th> <Ul> <Li> History </Li> <Li> Types </Li> <Li> Classification </Li> </Ul> </Th> </Tr> <Tr> <Td> <Ul> <Li> History of economics </Li> <Li> Economic history (academic study) </Li> <Li> Schools of economics </Li> </Ul> <Ul> <Li> Microeconomics </Li> <Li> Macroeconomics </Li> <Li> Methodology </Li> <Li> Heterodox economics </Li> <Li> JEL classification codes </Li> </Ul> </Td> </Tr> <Tr> <Th> <Ul> <Li> Concepts </Li> <Li> Theory </Li> <Li> Techniques </Li> </Ul> </Th> </Tr> <Tr> <Td> <Ul> <Li> Econometrics </Li> <Li> Economic growth </Li> <Li> Economic system </Li> <Li> Experimental economics </Li> <Li> Mathematical economics </Li> <Li> Game theory </Li> <Li> Post-scarcity </Li> <Li> Market </Li> <Li> National accounting </Li> </Ul> </Td> </Tr> <Tr> <Th> By application </Th> </Tr> <Tr> <Td> <Ul> <Li> Agricultural </Li> <Li> Behavioral </Li> <Li> Business </Li> <Li> Computational </Li> <Li> Cultural </Li> <Li> Demographic </Li> <Li> Development </Li> <Li> Digitization </Li> <Li> Ecological </Li> <Li> Education </Li> <Li> Environmental </Li> <Li> Evolutionary </Li> <Li> Expeditionary </Li> <Li> Geography </Li> <Li> Health </Li> <Li> Industrial organization </Li> <Li> Information </Li> <Li> International </Li> <Li> Knowledge </Li> <Li> Labour </Li> <Li> Law </Li> <Li> Managerial </Li> <Li> Monetary / Financial </Li> <Li> Natural resource </Li> <Li> Organizational </Li> <Li> Personnel </Li> <Li> Public / Welfare economics </Li> <Li> Regional </Li> <Li> Rural </Li> <Li> Service </Li> <Li> Social </Li> <Li> Urban </Li> <Li> Welfare </Li> </Ul> </Td> </Tr> <Tr> <Th> Lists </Th> </Tr> <Tr> <Td> <Ul> <Li> Economists </Li> <Li> Publications (journals) </Li> </Ul> </Td> </Tr> <Tr> <Td> <Ul> <Li> Business and economics portal </Li> </Ul> </Td> </Tr> <Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> </Table> <Tr> <Th> Economics </Th> </Tr>

For a commodity to function effectively as a medium of exchange it must be