Division of labor combines specialization and the partition of a complex production task into several, or many, sub-tasks. Its importance in economics lies in the fact that a given number of workers can produce far more output using division of labor compared to the same number of workers each working alone. Interestingly, this is true even if those working alone are expert artisans. The production increase has several causes. According to Adam Smith, these include increased dexterity from learning, innovations in tool design and use as the steps are defined more clearly, and savings in wasted motion changing from one task to another.

Though the scientific understanding of the importance of division of labor is comparatively recent, the effects can be seen in most of human history. It would seem that exchange can arise only from differences in taste or circumstance. But division of labor implies that this is not true. In fact, even a society of perfect clones would develop exchange, because specialization alone is enough to reward advances such as currency, accounting, and other features of market economies.

In the early 1800s, David Ricardo developed a theory of comparative advantage as an explanation for the origins of trade. And this explanation has substantial power, particularly in a pre-industrial world. Assume, for example, that England is suited to produce wool, while Portugal is suited to produce wine. If each nation specializes, then total consumption in the world, and in each nation, is expanded. Interestingly, this is still true if one nation is better at producing both commodities: even the less productive nation benefits from specialization and trade.

In a world with industrial production based on division of labor, however, comparative advantage based on weather and soil conditions becomes secondary. Ricardo himself recognized this in his broader discussion of trade, as Meoqui points out. The reason is that division of labor produces a cost advantage where none existed before—an advantage based simply on specialization. Consequently, even in a world without comparative advantage, division of labor would create incentives for specialization and exchange.

Origins

The Neolithic Revolution, with its move to fixed agriculture and greater population densities, fostered specialization in both production of consumer goods and military protection. As Plato put it:

This idea of the city-state, or polis, as a nexus of cooperation directed by the leaders of the city is a potent tool for the social theorist. It is easy to see that the extent of specialization was limited by the size of the city: a clan has one person who plays on a hollow log with sticks; a moderately sized city might have a string quartet; and a large city could support a symphony.

One of the earliest sociologists, Muslim scholar Ibn Khaldun (1332-1406), also emphasized what he called “cooperation” as a means of achieving the benefits of specialization: This sociological interpretation of specialization as a consequence of direction, limited by the size of the city, later motivated scholars such as Emile Durkheim (1858-1917) to recognize the central importance of division of labor for human flourishing.

Smith’s Insight

It is common to say that Adam Smith “invented” or “advocated” division of labor. Such claims are simply mistaken, on several grounds (see, for a discussion, Kennedy 2008). Smith described how decentralized market exchange fosters division of labor among cities or across political units, rather than just within them as previous thinkers had done. Smith had two key insights: First, division of labor would be powerful even if all human beings were identical, because differences in productive capacity are learned. Smith’s parable of the “street porter and the philosopher” illustrates the depth of this insight. As Smith put it:

Second, the division of labor gives rise to market institutions and expands the extent of the market. Exchange relations relentlessly push against borders and expand the effective locus of cooperation. The benefit to the individual is that first dozens, then hundreds, and ultimately millions, of other people stand ready to work for each of us, in ways that are constantly being expanded into new activities and new products.

Smith gives an example—the pin factory—that has become one of the central archetypes of economic theory. As Munger (2007) notes, Smith divides pin-making into 18 operations. But that number is arbitrary: labor is divided into the number of operations that fit the extent of the market. In a small market, perhaps three workers, each performing several different operations, could be employed. In a city or small country, as Smith saw, 18 different workers might be employed. In an international market, the optimal number of workers (or their equivalent in automated steps) would be even larger.

The interesting point is that there would be constant pressure on the factory to (a) expand the number of operations even more, and to automate them through the use of tools and other capital; and to (b) expand the size of the market served with consequently lower-cost pins so that the expanded output could be sold. Smith recognized this dynamic pressure in the form of what can only be regarded today as a theorem, the title of Chapter 3 in Book I of the Wealth of Nations: “That the Division of Labor is Limited by the Extent of the Market.” George Stigler treated this claim as a testable theorem in his 1951 article, and developed its insights in the context of modern economics.

Still, the full importance of Smith’s insight was not recognized and developed until quite recently. James Buchanan presented the starkest description of the implications of Smith’s theory (James Buchanan and Yong Yoon, 2002). While the bases of trade and exchange can be differences in tastes or capacities, market institutions would develop even if such differences were negligible. The Smithian conception of the basis for trade and the rewards from developing market institutions is more general and more fundamental than the simple version implied by deterministic comparative advantage.

Division of labor is a hopeful doctrine. Nearly any nation, regardless of its endowment of natural resources, can prosper simply by developing a specialization. That specialization might be determined by comparative advantage, lying in climate or other factors, of course. But division of labor alone is sufficient to create trading opportunities and the beginnings of prosperity. By contrast, nations that refuse the opportunity to specialize, clinging to mercantilist notions of independence and economic self-sufficiency, doom themselves and their populations to needless poverty.

About the Author Michael Munger is the Director of the PPE Program at Duke University.