In 1980, the population of the People’s Republic of China numbered close to a billion, and most were among the poorest people on earth. China produced barely a third as much steel as the US. Thirty five years later, it makes more steel in six weeks than the US does in a year, and has engineered the greatest fall in poverty in world history. Set beside the arrival of China into the global economy, no event since the industrial revolution has had a greater impact — not the financial crisis, nor even the collapse of the Soviet Union.

The Middle Kingdom is still — just — the world’s most populous country, but the number of its people that are of working age is on a downward trajectory. There is growing evidence of labour shortages, wages rising faster than productivity, and of the flow of migrant labour from the rural interior slowing sharply. Named for the Nobel Prize-winner Sir Arthur Lewis, countries that hit this Lewis Turning Point usually see economic growth fall. Handling lower growth will preoccupy China’s rulers in the decades to come, and provide the rest of the world with much to think about.

It is important not to exaggerate the significance of this turning point. While the sheer number of its people mesmerises the outside world, China has long been far more than a sweatshop. Closer examination shows a pattern of growth based more upon increased capital than labour, and by combining the two more cleverly. In recent years, investment has made up more than half of GDP, while the reforms launched by Deng Xiaoping in the late 1970s triggered a 30 year-long spurt of productivity growth.