A Very Brief Introduction to Adam Smith’s Wealth of Nations

The Inquiry into the Nature and Causes of the Wealth of Nations (WoN hereafter) was published on 9th March, 1776. It was advertised in the concluding paragraph of Theory of Moral Sentiments (1759). This blog post is a very brief introduction to Adam Smith’s theory of political economy as presented in the WoN. According to John Rae, the biographer of Smith, the WoN ‘took twelve years to write, and was in contemplation for probably twelve years before that.’ Smith never engaged in any commercial activity unlike his predecessor, Richard Cantillon or his successor, David Ricardo, yet his insights into the working of the competitive economy is intellectually deep and of enduring relevance. His intellectual acquaintances include David Hume, Francois Quesnay, Jacques Turgot and Voltaire.

WoN is divided into 5 books: Book I presents a detailed examination of how labour becomes productive, and contains a theory of supply (of output). On what factors does the annual supply of commodities depend? Book II builds on this and contains a theory of accumulation (of capital stock). The growth policies undertaken by various nations form the content of Book III. The existing theories of political economy are critically appraised in Book IV; this book also includes the policy effects of these theories. Finally, in Book V, a theory of public finance – the theory of the revenue, expenditure and borrowing of the government – is outlined. Given the recurring themes of economic growth and development in this blog, the title of books I and II deserve to be quoted in full.

Book I: Of the Causes of Improvement in the productive Powers of Labour, and of the Order according to which its Produce is naturally distributed among the different Ranks of the People

Book II: Of the Nature, Accumulation, and Employment of Stock

In other words, the first book contains a theory of income distribution and the second contains a theory of economic growth. Recent research has noted the similarities between Smith’s theory of economic growth and neoclassical ‘new economic growth theory’ of Romer; in fact, Smith’s theory clearly emerges as a superior one.

The ‘necessaries and conveniences of life’, according to Smith, are produced by labour. That is, labour produces the annual aggregate supply of commodities and services. The nation is considered better supplied if the proportion between the annual aggregate supply and annual population is high. To expand this definition and adopting modern terminology, we can say that this idea of Smith corresponds to that of output per capita (for example, a high GDP per capita is favoured over a low GDP per capita). Further, Smith asks: what determines the output per capita? According to Smith, there are two factors which determine this proportion. (1) The productivity of labour, and (2) the ratio of workers employed in physical and human capital generation to other workers. Smith uses a different terminology: the ratio of productive to unproductive labour. The number of workers employed in physical and human capital formation is necessarily in proportion to the capital advanced in these sectors. And, labour productivity depends on the capital advanced. But, what is there in Smith’s theory of economic growth which ensures that the growth in aggregate supply is validated by an equivalent growth in aggregate demand?

Smith’s WoN, particularly the first 2 books, is of much contemporary relevance in understanding the socio-cultural idea of ‘subsistence wage’. Also, it contains a rich exposition of productivity unlike the ‘blackbox’ of productivity commonly found in the Solow-type growth theory. Smith’s WoN contains both logical rigour as well as rich prose, and together they vastly enrich our understanding of economic phenomena.