In 1865, English economist William Stanley Jevons noticed a paradox in Britain’s coal consumption. Steam engines had grown far more efficient over the previous six decades, and most observers had expected this efficiency to cut demand for coal. Instead, coal consumption had grown eight-fold.

Part of the explanation was Thomas Newcomen’s coal-fired steam engine, invented in 1712. The engine was built to pump water out of coal mines, which let miners dig deeper and produce more coal. The added supply lowered prices, helping make it economically worthwhile to install steam engines in textile mills, ironworks, and, eventually, railways. Expanded use of coal raised the demand for it, which justified still deeper mines, which required still better pumps. British coal output rose from roughly 3 million tons around 1700 to a peak of around 290 million tons in 1913. More efficient production, Jevons argued, had raised rather than reduced demand for coal.

Coal drove innovation flywheels across the British economy. Cheaper coal and more powerful engines made it cheaper to produce iron, cloth, and hundreds of other goods. Lower input costs raised real incomes and democratized demand for new and existing goods. Cheap coal also made railways possible, enabling manufacturers to deliver an expanding output of less-expensive goods to new markets at home and abroad.

These innovations also helped raise employment levels. Though steam-powered looms displaced hand-loom weavers, the mining workforce grew from a few thousand to more than a million. Total British employment rose alongside technologies that had been forecast to destroy jobs. The main question on the public agenda was not worklessness, but how to alleviate the economic and social frictions of industrialization.

Today, code has reached its coal moment. Thanks to artificial intelligence, code production is picking up speed, adding vast new supplies of a basic input in the same way technological change and demand interacted to increase coal supplies.

Read more in National Affairs.