Adam Smith’s Pin Factory: Capital vs division of labour

Did Smith learn the wrong lesson from his factory tours?

This is a republished version of an original article from my old blog.

Like many well-trained economists, I took Adam Smith’s argument about the productivity gains being caused by the division of labour at face value. It wasn’t until I read Joan Robinson dismiss the argument in her 1973 textbook An Introduction to Modern Economics that I began to really put the effort into understanding the division of labour. I finally realised its incoherence as an explanation for productivity gains, but also that the pin factory story could provide valuable lessons about economics nonetheless.

Robinson dismisses Smith by suggesting that people can equally divide their own labour across different tasks through time. The 18 distinct operations Smith recounts could just as easily be conducted by the same labourer on 18 different days to generate the same output per person over an 18 day period as in the case where labour is divided between workers.

Further, the fact that relatively unskilled labour could perform any of these tasks adds to the case that it is not specialist skills from the division of labour at play in generating productivity gains. One-way causality from the division of labour to productivity gains is a highly problematic story.

But that leaves open the question about the actual mechanism that provided the enormous productivity gains in the pin factories of the mid-1700s.

Instead of Smith’s division of labour hypothesis, let me propose a capital investment hypothesis to explain the productivity of his pin factory. This hypothesis suggests that it is the technical nature of capital that determines the way labour will be divided across tasks to maximise output and that the division of labour responds to capital investment. The causality goes from capital investment to labour division.

To guide my inquiry I use the structured approach I have advocated for in the past, confronting economic issues by first asking questions about aggregation. For example, why are there 18 tasks to make a pin, not 5, 9, 16, or 37? Why are 18 workers in one pin factory and not 9 in one factory and 9 in another owned by a different entity? 

The answer to these questions is capital. The image above (source) shows the tools and equipment used in the pin factories described by Smith. Notice that the tools and machines in the picture have been designed to more efficiently perform distinct parts of the pin-making process. It is the way the tools have been designed to efficiently break down the task of making pins that leads to the labour division to ‘man the tools’.

Smith came close to instead presenting the capital investment hypothesis. He says

…a workman not educated to this business (which the division of labour has rendered a distinct trade), nor acquainted with the use of the machinery employed in it (to the invention of which the same division of labour has probably given occasion), could scarce, perhaps, with his utmost industry, make one pin in a day, and certainly could not make twenty. [my emphasis]

He suggests that it is the division of labour that has probably given rise to the machines, rather than the machines themselves giving rise to the division of labour. But this logic comes undone later in the paragraph, even though he ignores the inconsistency in his argument.

…the important business of making a pin is, in this manner, divided into about eighteen distinct operations, which, in some manufactories, are all performed by distinct hands, though in others the same man will sometimes perform two or three of them. I have seen a small manufactory of this kind where ten men only were employed, and where some of them consequently performed two or three distinct operations. [my emphasis]

Even based on Smith’s own observations it is the tools and machines that generate the 18 tasks. People can, and do, perform more than one of them. So how exactly how did the division of labour give rise to the invention of the necessary machines that generate 18 tasks with only ten men?

If it was the division of labour that led to increased productivity, labour could just as easily be divided between firms. The fact that pin factories, even with only ten men, still performed all 18 tasks, instead of specialising in just 10 tasks, is clear evidence that there is something special and coordinated about the tasks themselves that arise from the particular capital investments. The tools and machines are designed to be compatible with each other, and if part of the process is done outside the firm, each of the two firms would inevitably be tied to the same compatible capital equipment, and would therefore find gains by merging into a single firm.

When we ask questions about the timing of investment in machines we can more sharply distinguish between the division of labour and capital hypotheses. If it was only after the machines were introduced that labour was divided in a particular way, then that is evidence for the capital hypothesis. If labour was divided into 18 tasks prior to the investment in machines, achieving the same tasks in the absence of tools, then the division of labour hypothesis holds.

Indeed, the prediction of the capital investment hypothesis is that labour task specialisation responds to capital investments in either direction—either with more division of labour, or consolidation of tasks by a single labourer.

A modern test of these predictions could be garbage collection. With rear-loading trucks, labour is divided between driving the truck and loading the bins. But with more advanced side-loading trucks with robotic arms, the labour is once again undivided between driving the truck and collecting the bins. The progression of capital technology determines the division of tasks.

Like many stories in economics, the division of labour as a productivity-enhancer has been approached far too narrowly. There are many economic lessons in the story of the pin factory, and if we probed deeper we could understand more about what considerations determine the boundaries of firms, why firms are internally not-structured around market principles, and other important questions about how we coordinate productive activities. But a structured approach to economic inquiry is required to turn Smith’s pin factory into a useful learning tool. The same applies to other stories, like economists favourite Robinson Crusoe story about specialisation and equilibrium. But that will have to wait for another time.