<P> It is the second most cited book in the social sciences published before 1950, behind Karl Marx's Capital . </P> <P> An important theme that persists throughout the work is the idea that the economic system is automatic, and, when left with substantial freedom, able to regulate itself . This is often referred to as the "invisible hand ." The ability to self - regulate and to ensure maximum efficiency, however, is limited by externalities, monopolies, tax preferences, lobbying groups, and other "privileges" extended to certain members of the economy at the expense of others . </P> <Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (March 2017) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (March 2017) (Learn how and when to remove this template message) </Td> </Tr>

Who was the wealth of nations written for