The principal purpose, however, has been to loosen the claw-like grasp that scarcity economics has held over our working lives, and to diminish our corresponding and unsustainable preoccupation with economic growth. For by recognizing that many of the core assumptions that underwrite our economic institutions are an artifact of the agricultural revolution, amplified by our migration into cities, frees us to imagine a whole range of new, more sustainable possible futures for ourselves, and rise to the challenge of harnessing our restless energy, purposefulness, and creativity to shaping our destiny.

In a recent article called “Are Ideas Getting Harder to Find?,” economists from Stanford and LSE analysed this phenomenon quantitatively. Across a range of industries, across firms, and in the aggregate economic data they found the same thing: progress becomes harder and harder. Based on their numbers, in order to double our overall level of technological advancement, we need to put in, conservatively, four times as much research effort as we did for the previous doubling. To illustrate, suppose (simplistically) that initially it took 10 person-years of “research” to double the world’s level of technological advancement: to move from knowing only how to make a stone axe to knowing how to make both an axe and a spear. In order to get the next doubling of technological progress, it would take 40 person-years of research. The next doubling would take 160 person-years, then 640 person-years, then 2,560 person-years, and so on.

Here are two reasons why this might happen. First, perhaps, as political economist Benjamin Friedman argues, people are more morally motivated in times of economic growth. When the economy is growing, everyone can be better off than they were in the past. This means, Friedman argues, that citizens will worry less about how their life compares to the lives of people around them and will be more supportive of generous, open, and tolerant social policies. And if you look at the historical record, he claims, countries tend to make moral progress—becoming fairer, more open, and more egalitarian—during higher-growth periods, and they tend to morally regress during periods of stagnation.

A second reason ties back to our earlier discussion of cultural evolution. When technological innovation is possible, there are great economic gains to be had from critical thinking and scientific inquiry; and since economically successful cultures gain more members, cultural evolution currently selects for traits conducive to science. As a side effect, so this argument goes, we apply our critical capacities to moral issues, too, and therefore make moral progress. In a stagnant world, the economic reasons to engage in critical thinking and scientific inquiry would be much weaker. Instead, other values would be selected for, such as those favouring hierarchy and conformity, which have guided so many societies in the past.

As former Federal Reserve chairman Alan Greenspan observed in the remark that began this chapter, modern economic growth in developed economies is largely about better and more complex rather than bigger and more.

My critique of GDP measurement in practice relates to its inability to report sufficiently accurately what it is intended to measure: the value of economic output. And pronouncements based on such data about long-run trends in income or the rate of increase of productivity should be taken with a grain of salt – or several. When pundits fret over whether the latest figure for GDP growth is an annual rate of 1.8 per cent or 1.9 per cent, they are fussing over differences that are insignificant in relation to the fundamental and inescapable uncertainties in the data they are citing.