Invisible hand
The invisible hand is a metaphor inspired by the Scottish economist and moral philosopher Adam Smith that describes the incentives which free markets sometimes create for self-interested people to accidentally act in the public interest, even when this is not something they intended. Smith originally mentioned the term in two specific, but different, economic examples. It is used once in his Theory of Moral Sentiments when discussing a hypothetical example of wealth being concentrated in the hands of one person, who wastes his wealth, but thereby employs others. More famously, it is also used once in his Wealth of Nations, when arguing that governments do not normally need to force international traders to invest in their own home country. In both cases, Adam Smith speaks of an invisible hand, never of the invisible hand.
Going far beyond the original intent of Smith's metaphor, twentieth-century economists, especially Paul Samuelson, popularized the use of the term to refer to a more general and abstract conclusion that truly free markets are self-regulating systems that always tend to create economically optimal outcomes, which in turn cannot be improved upon by government intervention. The idea of trade and market exchange perfectly channelling self-interest toward socially desirable ends is a central justification for newer versions of the laissez-faire economic philosophy which lie behind neoclassical economics.
Adam Smith was a proponent of less government intervention in his own time, and of the possible benefits of a future with more free trade both domestically and internationally. However, in a context of discussing science more generally, Smith himself once described "invisible hand" explanations as a style suitable for unscientific discussion, and he never used it to refer to any general principle of economics. His argumentation against government interventions into markets were based on specific cases, and were not absolute. Putting the invisible hand itself aside, while Smith's various ways of presenting the case against government management of the economy were very influential, they were also not new. Smith himself cites earlier enlightenment thinkers such as Bernard Mandeville. Smith's invisible hand argumentation may have also been influenced by Richard Cantillon and his model of the isolated estate.
Because the modern use of this term has become a shorthand way of referring to a key neoclassical assumption, disagreements between economic ideologies are now sometimes viewed as disagreement about how well the "invisible hand" is working. For example, it is argued that tendencies that were nascent during Smith's lifetime, such as large-scale industry, finance, and advertising, have reduced the effectiveness of the supposed invisible hand.
Alternatively, it can be misused or misinterpreted as a conspiracy to use a hidden mechanism to control markets or society, or as an existing conspiracy that a powerful "invisible hand" exists.
History of the terms and concepts
The term "invisible hand" has classical roots, and it was relatively widely used in 18th-century English. Adam Smith's own usage of the term did not attract much attention until many generations after his death. In his early unpublished essay on The History of Astronomy he specifically described this type of explanation as a common and unscientific way of thinking. Smith wrote that superstitious people, or people with no time to think philosophically about complex chains of cause and effect, tend to explain irregular, unexpected natural phenomena such as "thunder and lightning, storms and sunshine", as acts of favour or anger performed by "gods, daemons, witches, genii, fairies". For this reason the philosophical or scientific study of nature can only begin when there is social order and security, so that people are not living in fear, and can be attentive. Because of this background, a wide range of interpretations have been given to the fact that Smith himself used the metaphor twice when discussing economic topics. On one extreme it has been argued that Smith was literally suggesting that divine intervention is at play in the economy, and at the other extreme it has been suggested that Smith's use of this metaphor shows that he was being sarcastic.The modern conception of a free market causing the best possible economic result, which is now commonly associated with the term "invisible hand", also developed further, going beyond Smith's conception. It has been influenced by arguments for free markets found not only in Smith's works, but also by earlier writers such as especially Bernard Mandeville, and later more mathematical approaches by economists such as Pareto and Marshall.
Adam Smith's use of the term in economics
''The Wealth of Nations''
The invisible hand is explicitly mentioned only once in the Wealth of Nations, in a specialized chapter not about free trade but about capital investment, which discusses the concern that international merchants might choose to invest in foreign countries. Smith argues that a self-interested investor will have a natural tendency to employ his capital as near home as he can, as long as the home market does not give much lower returns than other alternatives. This in turn means...As noted by William D. Grampp, this example involves "a particular condition that may or may not be present in a transaction on a competitive market". Essentially, the invisible hand refers to the unintended positive consequences self-interest has on the promotion of community welfare. Nevertheless, Smith draws a practical implication in this case is that legislators should not intervene too hastily in many cases:
According to Grampp:
''The Theory of Moral Sentiments''
Smith's first use of the invisible hand metaphor occurs in The Theory of Moral Sentiments in Part IV, Chapter 1, where he describes a selfish landlord being led by an invisible hand to distribute his harvest to those who work for him. This passage concerns the distribution of wealth: the poor receive the "necessities of life" after the rich have gratified "their own vain and insatiable desires". It has been noted that in this passage Smith seems to equate the invisible hand to "Providence", implying a divine plan.Although this passage concerns an economic topic in a broad sense, it does not concern "the invisible hand" of the free market as understood by twentieth century economists, but is instead about income distribution. There is no repeat of this argumentation in Smith's comprehensive work on economics in his later Wealth of Nations, and income distribution is not a central concern of modern neoclassical market theory. As Blaug noted in the New Palgrave Dictionary of Economics this passage "dispels the belief that Smith meant one thing and one thing only by the metaphor of 'the invisible hand'." Grampp has claimed that if there is any connection between this passage and Smith's other one, "it has not been demonstrated with evidence from what Smith actually wrote".
The reinterpretation by modern economists
In contrast to Smith's own usage, the "invisible hand" today is often seen as being specifically about the benefits of voluntary transactions in a free market, and is treated as a generalizable rule. Paul Samuelson's comments in his Economics textbook in 1948 made the term popular and gave it a new meaning. The phrase was not originally commonly referred to among economists before the twentieth century. Alfred Marshall never used it in his Principles of Economics textbook and neither does William Stanley Jevons in his Theory of Political Economy. Samuelson's remark was as follows:In this interpretation, the theory is that the Invisible Hand states that if each consumer is allowed to choose freely what to buy and each producer is allowed to choose freely what to sell and how to produce it, the market will settle on a product distribution and prices that are beneficial to all the individual members of a community, and hence to the community as a whole. The reason for this is that self-interest drives actors to beneficial behavior in a case of serendipity. Efficient methods of production are adopted to maximize profits. Low prices are charged to maximize revenue through gain in market share by undercutting competitors. Investors invest in those industries most urgently needed to maximize returns, and withdraw capital from those less efficient in creating value. All these effects take place dynamically and automatically.
Since Smith's time, this concept has been further incorporated into economic theory. Léon Walras developed a four-equation general equilibrium model that concludes that individual self-interest operating in a competitive market place produces the unique conditions under which a society's total utility is maximized. Vilfredo Pareto used an Edgeworth box contract line to illustrate a similar social optimality. Ludwig von Mises, in Human Action uses the expression "the invisible hand of Providence", referring to Marx's period, to mean evolutionary meliorism. He did not mean this as a criticism, since he held that secular reasoning leads to similar conclusions. Milton Friedman, a Nobel Memorial Prize winner in economics, called Smith's Invisible Hand "the possibility of cooperation without coercion." Kaushik Basu has called the First Welfare Theorem the Invisible Hand Theorem.
Some economists question the integrity of how the term "invisible hand" is currently used. Gavin Kennedy, Professor Emeritus at Heriot-Watt University in Edinburgh, Scotland, argues that its current use in modern economic thinking as a symbol of free market capitalism is not reconcilable with the rather modest and indeterminate manner in which it was employed by Smith. In response to Kennedy, Daniel Klein argues that reconciliation is legitimate. Moreover, even if Smith did not intend the term "invisible hand" to be used in the current manner, its serviceability as such should not be rendered ineffective. In conclusion of their exchange, Kennedy insists that Smith's intentions are of utmost importance to the current debate, which is one of Smith's association with the term "invisible hand". If the term is to be used as a symbol of liberty and economic coordination as it has been in the modern era, Kennedy argues that it should exist as a construct completely separate from Adam Smith since there is little evidence that Smith imputed any significance onto the term, much less the meanings given it at present.
The former Drummond Professor of Political Economy at Oxford, D. H. MacGregor, argued that:
Harvard economist Stephen Marglin argues that while the "invisible hand" is the "most enduring phrase in Smith's entire work", it is "also the most misunderstood."
According to Emma Rothschild, Smith was actually being ironic in his use of the term. Warren Samuels described it as "a means of relating modern high theory to Adam Smith and, as such, an interesting example in the development of language."
Proponents of liberal economics, for example Deepak Lal, regularly claim that the invisible hand allows for market efficiency through its mechanism of acting as an indicator of what the market considers important, or valuable.