What Technology Wants (14 page)

But there is a puzzle. The necessary ingredients of the scientific method are conceptual and fairly low tech: a way to record, catalog, and communicate written evidence and the time to experiment. Why didn't the Greeks invent it? Or the Egyptians? A time traveler from today could journey back to that era and set up the scientific method in ancient Alexandria or Athens without much trouble. But would it catch on?

Maybe not. Science is costly for an individual. Sharing results is of marginal benefit if you are chiefly seeking a better tool for today. Therefore, the benefits of science are neither apparent nor immediate for individuals. Science requires a certain density of leisured population willing to share and support failures to thrive. That leisure is generated by pre-science inventions such as the plow, grain mills, domesticated power animals, and other techniques that permit a steady surplus of food for large numbers of people. In other words, science needs prosperity and populations.

Outside the reign of science and technology a growing population will collapse upon itself as it meets Malthusian limits. But inside the reign of science a growing population creates a positive feedback loop wherein more people participate in scientific innovation and purchase the results, driving more innovation, which brings better nutrition, more surplus, and more population, which feed the cycle further.

Just as an engine tames its fire, channeling its explosive energy to-ward work, science tames population growth, channeling its explosive energy toward prosperity. As population rises, so does progress, and vice versa. The two growths are heavily correlated.

World Population in Civilization.
A typical chart showing world population during the last 12,000 years, including a short-term, 30-year projection into the future.

We have many examples in modern times of increasing populations suffering through declining living standards. That is happening in parts of Africa right now. On the other hand, throughout history it has been rare to see rising prosperity over the long term propelled by declining population. Declining population is almost always associated with declining prosperity. Even during the decimations of the black plague, when 30 percent of an area's population died, the change in living standards was uneven. Many of the overpopulated peasant regions in Europe and China prospered as their competition thinned out, but the quality of life for merchants and the upper class declined substantially. There was a redistribution of living standards, but not a net gain in progress during this time. The evidence from plagues is that population growth is necessary but not sufficient for progress.

Clearly, the roots of progress lie deep in the structured knowledge of science and technology. But the flowering of this progressive growth seems to also need the growth of large human populations. Historian Niall Ferguson believes that on the global scale, the origins of progress lie only in expanding population. According to this theory, in order to elevate populations beyond Malthusian limits you need science, yet it is the increase in the number of humans that ultimately drives science, and then prosperity. In this virtuous circle more human minds invent more things and in turn buy more inventions, including tools, techniques, and methods that will support more humans. Therefore, more human minds equal more progress. The economist Julian Simon called human minds “the ultimate resource.” In his calculation, more minds were the prime source of deep progress.

Whether population growth is the prime cause of progress or only a factor, population growth assists progress growth in two ways. First, a million individual minds applied to a problem are better than one. It's more likely someone will find a solution. Second, and more important, science is a collective action, and the emergent intelligence of shared knowledge is often superior to even a million individuals. The solitary scientific genius is a myth. Science is both the way we personally know things and the way we collectively know. The greater the pool of individuals in the culture, the smarter science gets.

The economy works in a similar way. Much of our current economic prosperity is due to population growth. The population of the United States has steadily grown over the past few centuries, ensuring a steadily expanding market for innovations. At the same time, world population has been expanding, ensuring economic growth worldwide. World population has also grown in accessibility and desire as billions have moved from subsistence farming into the marketplace. But try to imagine the same rise in wealth in the past two centuries if the world market or the U.S. market had shrunk every year.

If it is true that progress expands as human population expands, then we should be worried. You may have seen the official graph of peak human population prepared by the United Nations. It is based on the best information we have about the global census of humans living today. The estimated peak number of humans on Earth keeps changing (downward) in each revision in the past decades, but the shape of its destiny does not. A typical UN chart for the next 40 years or so looks like this:

World Population Forecasts.
United Nations world population projections for the years 2002 to 2050, in billions, forecasted in 2002.

The problem this presents for understanding the origins of technological progress is that the chart always stops there, right at the year 2050. At the apex. It dares not look beyond the peak. So what happens after the population peaks? Does it sink, swim, or rise again? Why is that never shown? Most charts simply ignore the question, with no apology for the omission. Showing just one-half of the curve has been so common for so long that no one asks for the other half.

The only source I have found for a reliable projection of what happens on the other side of the peak of human population around 2050 is a set of UN scenarios for World Population in 2300, that is, for the next 300 years.

Keep in mind that a worldwide fertility rate below the replacement level of 2.1 children per woman means a long-term decline in global population, or negative population growth. The UN high scenario assumes average fertility remains at 1995 rates, or 2.35 children per woman. We already know this extreme version is not happening. Only a couple of countries out of 100-plus in the world have kept their reproduction rates that high. The middle scenario assumes that the average fertility dips below replacement levels of 2.1 for 100 years and then for some reason returns to replacement level for the next 200 years. The report suggests no possible reason why fertility rates would rise in a more developed world. The low scenario assumes 1.85 children per woman. Today every country in Europe is below 2.0, and Japan is at 1.34. Even this “low” scenario assumes a higher fertility in 200 years than what most developed countries currently have.

Estimated Long-Range World Population.
Three United Nations scenarios (high, medium, low) for world population in the next 300 years, from 2000 to 2300, in billions.

What's going on here? As countries become developed, their fertility rates drop. This drop-off has happened in every modernizing country, and this universal decrease in fertility rates is known as the “demographic transition.” The problem is that the demographic transition has no bottom. In developed countries the fertility rate keeps dropping. And dropping. Look at Europe (chart on the next page) or Japan. Their fertility rates are headed to zero. (Not zero population
growth,
which they long ago sank past, but zero population.) In fact, most countries, even developing countries, see their fertility rates dropping. Nearly half of the countries in the world are already below the replacement level.

Recent Fertility Rates in Europe.
The dotted line is the replacement level—the lowest rate by which a population group can replace itself.

In other words, as prosperity increases due to expanding population, fertility rates drop, which will shrink population. This might be a homeostasis feedback mechanism that reins in exponential rates of progress. Or it might be wrong.

The UN 2300 scenarios are scary, but the problem with these 300-year forecasts is that their dire scenario is not dire enough. The experts assume that even in the worst-case scenario fertility rates cannot go lower than the low rates found in places like Europe or Japan. Why do they assume this? Because it has never happened before. But of course this level of prosperity has never occurred before either. So far all evidence suggests that increased prosperity keeps lowering the number of children the average woman wants. What if global fertility rates keep dropping below the replacement rate of 2.1 offspring for every woman in developed countries and 2.3 in developing countries? The replacement rate is what is needed simply to maintain zero growth, to maintain a population, to not decline. An average rate of 2.1 offspring means a significant portion of women have to have three or four or five babies in order to counter the childless and those with only one or two babies. What countercultural force is at work prompting billions of modern, educated, working women to have three, four, or five babies? How many of your friends have four children? Or three? “Just a few” won't matter in the long run.

Keep in mind that an enduring global fertility rate only a little below the replacement level, say 1.9, will eventually, inevitably bring the world population to zero, because each year there are fewer and fewer babies. But zeroing out is not the worry. Long before the human population dropped to zero, the Amish and Mormons would save humankind with their prolific breeding and large families. The question is, if rising prosperity hinges on rising population, what happens to deep technological progress if there are centuries of slow population decline?

There are five scenarios, with five different assumptions about the nature of progress.

Perhaps technology makes having babies much easier, or much cheaper, though it is hard to imagine any way in which technology could make rearing three children any easier. Or perhaps there is social pressure to maintain the species or social status in having a lot of children. Maybe robotic nannies change everything and having more than two kids becomes fashionable. It is not impossible to speculate on ways to maintain a status quo. But even if global population leveled off and maintained a constant number, we don't have any experience that suggests that a stagnant population can produce rising progress.