The world has more than enough labour. Between 1980 and 2010, according to the McKinsey Global Institute, global nonfarm employment rose by about 1.1 billion, of which about 900m was in developing countries. The integration of large emerging markets into the global economy added a large pool of relatively low-skilled labour which many workers in rich countries had to compete with. That meant firms were able to keep workers' pay low. And low pay has had a surprising knock-on effect: when labour is cheap and plentiful, there seems little point in investing in labour-saving (and productivity-enhancing) technologies. By creating a labour glut, new technologies have trapped rich economies in a cycle of self-limiting productivity growth.
    Fear of the job-destroying effects of technology is as old as industrialisation. It is often branded as the lump-of-labour fallacy: the belief that there is only so much work to go round (the lump), so that if machines (or foreigners) do more of it, less is left for others. This is deemed a fallacy because as technology displaces workers from a particular occupation it enriches others, who spend their gains on goods and services that create new employment for the workers whose jobs have been automated away. A critical cog in the re-employment machine, though, is pay. To clear a glutted market, prices must fall, and that applies to labour as much as to wheat or cars.
    Where labour is cheap, firms use more of it. Carmakers in Europe and Japan, where it is expensive, use many more industrial robots than in emerging countries, though China is beginning to invest heavily in robots as its labour costs rise. In Britain a bout of high inflation caused real wages to tumble between 2007 and 2013. Some economists see this as an explanation for the unusual shape of the country's recovery, with employment holding up well but productivity and GDP performing abysmally.
    Productivity growth has always meant cutting down on labour. In 1900 some 40% of Americans worked in agriculture, and just over 40% of the typical household budget was spent on food. Over the next century automation reduced agricultural employment in most rich countries to below 5%, and food costs dropped steeply. But in those days excess labour was relatively easily reallocated to new sectors, thanks in large part to investment in education. That is becoming more difficult. In America the share of the population with a university degree has been more or less fiat since the 1990s. In other rich economies the proportion of young people going into higher education has gone up, but few have managed to boost it much beyond the American level.  It can be inferred from Paragraph 1 that ______.