Increasing the Number of Researchers to Perpetuate Technological Progress

Over the past century, we’ve seen relatively steady, though slowing, technological progress. Sustaining this progress is the result of a balancing act: every year, further progress gets harder, but every year we exponentially increase the number of researchers and engineers. For instance, in the United States, research effort is over twenty times higher today than in the 1930s.27 The number of scientists in the world is doubling every couple of decades, such that at least three-quarters of all scientists who have ever lived are alive today.28 So far, exponential growth in the number of researchers has compensated for progress becoming harder over time.

So to think about whether we can sustain technological progress, we have to think about whether we can keep exponentially growing the number of researchers. Consider that there are two ways to do this. First, you can increase the share of the population that is devoted to research. Indeed, we’ve been doing a lot of that, so that’s been the source of most of US technological progress in the last few decades. Technology-driven growth of US per-capita incomes has averaged about 1.3 percent per year. A full percentage point of that comes from increasing the fraction of the population doing R&D and from improving the allocation of talent, such as by reducing gender and racial discrimination.29

The second way by which you can increase the number of researchers is by increasing the total size of the labour force: that is, you can grow the population. Over the last few decades, population growth has contributed about 0.3 percentage points to the United States’ technologically driven per-capita growth rate.30

Historically, increasing population sizes have been a major factor in rates of technological progress. As Nobel Prize–winning economist Michael Kremer has noted, sheer population size seems to explain a big part of the very long-run comparative development of different geographic regions. With the end of the most recent ice age in 10,000 BC, five regions of the world became mutually isolated from one another: the Eurasian and African continents, the Americas, Australia, Tasmania, and Flinders Island.31 By AD 1500, they had dramatically diverged technologically. The more populous a region was in 10,000 BC, the more complex their technology was by AD 1500. Eurasia had the most complex technology; the Americas followed, with cities, agriculture, and the Aztec and Mayan civilisations; Australia was in an intermediate position; while Tasmania had seen little technological development, and the population of Flinders Island had died out completely.32 The larger the population, the more opportunities there were for people to invent new tools and techniques—more minds meant more inventions. And once a tool had been invented, that innovation would spread far and wide.