In Book I, which is named <em>Book of the Causes of Improvement in the productive Powers of Labor</em>, division of labor causes a greater increase in production than any other factor. The division of labor should be determined between laborers and employers, although it's limited by the extent of the market.
<em>An Inquiry into the Nature and Causes of the Wealth of Nations</em> is a compilation of texts written by the Scottish economist and philosopher Adam Smith. It was first published in 1776 and it talks about different topics like the division of labor, markets, and productivity.