Robert E Lucas won the Nobel Prize in economics in 1995. Here’s an article published in May 2004, “The Industrial Revolution: Past and Future” which is useful for us in the context of the economic history of the world. Excerpts below the fold:
. . . we now have a reliable picture of production in the entire world, both rich and poor countries. Let us review the main features of this picture, beginning with population estimates. Over the 40-year period from 1960 through 2000, world population grew from about 3 billion to 6.1 billion, or at an annual rate of 1.7 percent. These numbers are often cited with alarm, and obviously the number of people in the world cannot possibly grow at 2 percent per year forever. But many exponents of what a friend of mine calls the “economics of gloom” go beyond this truism to suggest that population growth is outstripping available resources, that the human race is blindly multiplying itself toward poverty and starvation. This is simply nonsense.
There is, to be sure, much poverty and starvation in the world, but nothing could be further from the truth than the idea that poverty is increasing. Over the same period during which population has grown from 3 billion to 6.1 billion, total world production has grown much faster than population, from $6.5 trillion in 1960 to $31 trillion in 2000. (All the dollar magnitudes I cite, from the Penn World Table or any other source, will be in units of 1985 U.S. dollars.) That is, world production was nearly multiplied by five over this 40-year period, growing at an annual rate of 4 percent. Production per person—real income—thus grew at 2.3 percent per year, which is to say that the living standard of the average world citizen more than doubled. Please understand: I am not quoting figures for the advanced economies or for a handful of economic miracles. I am not excluding Africa or the communist countries. These are numbers for the world as a whole. The entire human race is getting rich, at historically unprecedented rates. The economic miracles of East Asia are, of course, atypical in their magnitudes, but economic growth is not the exception in the world today: It is the rule.
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Comparison to earlier centuries
The striking thing about postwar economic growth is how recent such growth is. I have said that total world production has been growing at over 4 percent since 1960. Compare this to annual growth rates of 2.4 percent for the first 60 years of the 20th century, of 1 percent for the entire 19th century, of one-third of 1 percent for the 18th century. For these years, the growth in both population and production was far lower than in modern times. Moreover, it is fairly clear that up to 1800 or maybe 1750, no society had experienced sustained growth in per capita income. (Eighteenth century population growth also averaged one-third of 1 percent, the same as production growth.) That is, up to about two centuries ago, per capita incomes in all societies were stagnated at around $400 to $800 per year. But how do we know this? After all, the Penn World Tables don’t cover the Roman Empire or the Han Dynasty. But there are many other sources of information.
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. . . I think it is accurate to say that we have not one but two theories of production: one consistent with the main features of the world economy prior to the industrial revolution and another roughly consistent with the behavior of the advanced economies today. What we need is an understanding of the transition.
One of these successful theories is the product of Smith, Ricardo, Malthus and the other classical economists. The world they undertook to explain was the world on the eve of the industrial revolution, and it could not have occurred to them that economic theory should seek to explain sustained, exponential growth in living standards. Their theory is consistent with the following stylized view of economic history up to around 1800. Labor and resources combine to produce goods—largely food, in poor societies—that sustain life and reproduction. Over time, providence and human ingenuity make it possible for given amounts of labor and resources to produce more goods than they could before. The resulting increases in production per person stimulate fertility and increases in population, up to the point where the original standard of living is restored. Such dynamics, operating over the centuries, account for the gradually accelerating increase in the human population and the distribution of that population over the regions of the earth in a way that is consistent with the approximate constancy of living standards everywhere. The model predicts that the living standards of working people are maintained at a roughly constant, “subsistence” level, but with realistic shares of income going to landowners, the theory is consistent as well with high civilization based on large concentrations of wealth.
This classical theory is not inconsistent with the enormous improvements in knowledge relevant to productivity that occurred long before the 18th century, improvements that supported huge population increases and vast wealth for owners of land and other resources. Increases in knowledge over the centuries also stimulated a large-scale accumulation of productive capital: shipbuilding, road and harbor construction, draining of swamps, and breeding and raising of animal herds for food and power. Capital accumulation, too, played a role in supporting ever larger populations. Yet under the Malthusian theory of fertility, neither new knowledge nor the capital accumulation it makes profitable is enough to induce the sustained growth in living standards of masses of people that modern economists take as the defining characteristic of the industrial revolution.
The modern theory of sustained income growth, stemming from the work of Robert Solow in the 1950s, was designed to fit the behavior of the economies that had passed through the demographic transition. This theory deals with the problem posed by Malthusian fertility by simply ignoring the economics of the problem and assuming a fixed rate of population growth. In such a context, the accumulation of physical capital is not, in itself, sufficient to account for sustained income growth. With a fixed rate of labor force growth, the law of diminishing returns puts a limit on the income increase that capital accumulation can generate. To account for sustained growth, the modern theory needs to postulate continuous improvements in technology or in knowledge or in human capital (I think these are all just different terms for the same thing) as an “engine of growth.” Since such a postulate is consistent with the evidence we have from the modern (and the ancient) world, this does not seem to be a liability of the theory.
The modern theory, based on fixed fertility, and the classical theory, based on fertility that increases with increases in income, are obviously not mutually consistent. Nor can we simply say that the modern theory fits the modern world and the classical theory the ancient world, because we can see traditional societies exhibiting Malthusian behavior in the world today. Increases since 1960 in total production in Africa, for example, have been almost entirely absorbed by increases in population, with negligible increases in income per capita. Understanding the progress of the industrial revolution as it continues today necessarily entails understanding why it is that Malthusian dynamics have ceased to hold in much of the contemporary world. Country after country has gone through a demographic transition, involving increases in the rate of population growth followed by decreases, as income continues to rise. Some of the wealthiest countries—Japan and parts of Europe—are just about maintaining their populations at current levels. People in these wealthy economies are better able to afford large families than people in poor economies, yet they choose not to do so.
If these two inconsistent theories are to be reconciled, with each other and with the facts of the demographic transition, a second factor needs to work to decrease fertility as income grows, operating alongside the Malthusian force that works to increase it. Gary Becker proposed long ago that this second factor be identified with the quality of children: As family income rises, spending on children increases, as assumed in Malthusian theory, but these increases can take the form of a greater number of children or of a larger allocation of parental time and other resources to each child. Parents are assumed to value increases both in the quantity of children and in the quality of each child’s life.
Please read the entire article carefully.