The generation of an economic surplus came after millennia of, at best, subsistence living. The explanation of why it happened when and where it did remains incomplete, though theories abound. Adam Smith wrote An Inquiry into the Nature and Causes of the Wealth of Nations just as the very first examples of industrial development were being established. His theory of economics was developed further as a consequence of industrialization and became in its turn influential on governments in shaping that process. More recently economic theory has played an overwhelmingly influential role in shaping the job of management itself.