Why were resources expunged from neo-classical economics?

Update: Read Martin Wolf’s conclusions on the debate

Something strange happened to economics about a century ago. In moving from classical to neo-classical economics — the dominant academic school today — economists expunged land — or natural resources. Neo-classical value theory — based on marginalism and subjective valuation — still makes a great deal of sense. Expunging natural resources from the way economists think about the world does not.

In classical economics, land, labour and capital were the three factors of production. With neo-classical economics, the standard production function had just two factors of production: capital and labour. Land — by which we mean the totality of natural resources — was then incorporated into capital.

All thinking about the world involves a degree of abstraction. Economics has taken this principle further than any other social science. This is a fruitful intellectual procedure. But it is also risky. The necessary process of abstraction may end up leaving essential aspects of the world out of the analysis. That can be intellectually crippling. I believe that that is exactly what has happened, in this case.

The idea that land and capital are the same thing is evidently ludicrous. It requires us to believe that the economic machine is self-sustaining — a sort of perpetual motion machine. Capital is the product of savings and investment. It is the result of human frugality and the invention required to imagine and create new capital goods. Labour is also — and in today’s circumstances, increasingly — a form of capital. Parents, governments and individual people invest in their own skills, so making themselves more productive. Yet there would be no economy — indeed no humanity — without a constant inflow of natural resources into the system: what lies above our heads (the sun and the atmosphere), what lies close to us (the soil, the seas and location itself) and what lies beneath us (fossil fuels, metals and minerals and heat). Humanity does not make these things; it exploits them. Some of these resources are also appropriable and so a source of unearned personal wealth.

Why did this compelling distinction disappear from economics? After all, no economist can believe that the economic system will move without a constant infusion of external resources.

One reason was that the classical world view implies diminishing returns. Since the supply of land was fixed, it would become ever scarcer. Rents — the price of resource scarcity — would rise, profits would fall and growth slow. But the economy did not show signs of diminishing returns. Technical progress seemed to offset any tendency towards diminishing returns. So assuming that land, like capital, could be effectively expanded, without limit, via land-augmenting technical progress, seemed to be the right thing to do.

Another reason may have been political. Henry George argued that resource rents are not a reward for the efforts of the owners, but the fruit of the efforts of others. It would be both just and efficient to socialise rents, he argued, and then use the proceeds to finance the infrastructure that makes resources valuable. But the powerful owners of natural resources wished to protect their unearned gains. In practice, therefore, the tax burden fell on labour and capital. Economics, one might argue, was pushed into supporting this way of organising economic life.

Yet it would seem to me that this way of thinking by economists is no longer sensible, if it ever was. Land must again be treated as separate from labour and capital.

First, resource scarcity is an increasingly pressing issue. It shows up in concerns over pollution (including global warming), in the discussion of “peak oil” and so forth. The idea that diminishing returns will become a more significant factor in the next century than in the past two seems to me to be compelling, now that modern economic growth has spread across the globe. So we need to return to economic models that incorporate resources, as a matter of course.

Second, in a globalised economy, taxing labour and capital will become increasingly difficult. That leaves land. The Australian government is right to want to extract the full rental value of its mineral resources for the benefit of the Australian people. Similarly, the people of the UK should wish to extract the rental value of London for their own use. The benefits of infrastructure investments that make London more productive would automatically be recouped if land rents were heavily taxed. Meanwhile, the taxation of capital and land could be reduced.

I can see the objection that natural resources are necessary for the operation of capital and labour. Thus, the distinction between land, labour and capital is hard to draw. I agree with this. But there are two responses: first, from the point of view of economics, resource scarcity may mean diminishing returns, which are economically important; second, some natural resources are not appropriable and can be treated as free (sunlight, for example), but others are indeed appropriable.

Thus, for both economic and political reasons, we should put natural resources into the heart of economics, thereby remedying a neoclassical mistake.

What do readers think?

Related reading:

Classical economics – Wikipedia
Neo-classical economics – Wikipedia

July 23: Martin Wolf gives his conclusions on the debate:

This ended up as a heated debate. Nobody will be surprised if I conclude that the result of the debate (often surprisingly ill-tempered) was pro-LVT 10, anti-LVT zero. I am surprised by some of what the anti-LVT proponents have said. I would have thought they would wish to open their minds a bit. I did and was persuaded of the case, as a result. Is not the purpose of such exchanges to learn from one another?

July 12: Martin Wolf responds to readers’ comments:

I don’t know whether classical economists saw entrepreneurship as a separate factor of production. The term was apparently introduced by the Irish economist Richard Cantillon in the 18th century. Jean-Baptiste Say coined the term “entrepreneur” in 1800. More recently, George W. Bush famously said the French did not have word for it! But it was surely Schumpeter who made the entrepreneur the central actor in economic life.