Fifty Inventions That Shaped the Modern Economy

they didn’t shape it by just producing more stuff, more cheaply. Each invention tugged on a complex web of economic connections.

many more people currently own a mobile phone than a flushing toilet.9

These fertile but geographically limited river valleys changed the way people got enough to eat:

Archaeological evidence also suggests that the early farmers had far worse health than their immediate hunter-gatherer forebears. With their diets of rice and grain, our ancestors were starved of vitamins, iron, and protein.

skyscrapers. But here’s the problem: if cheaply made, it will rot from the inside as water gradually seeps in through tiny cracks in the concrete and rusts the steel. This process is currently destroying infrastructure across the United States;* in twenty or thirty years’ time, China will be next. China poured more concrete in the three years after

the more ordinary people are able to produce, the more powerful people can confiscate.

To create those conditions on a scale sufficient to produce 160 million tons of ammonia a year—the majority of which is used for fertilizer—the Haber-Bosch process today consumes more than 1 percent of all the world’s energy.5

The moldboard plow cuts a long, thick ribbon of soil and turns it upside down.8 In dry ground, that’s a counterproductive exercise, squandering precious moisture. But in the fertile wet clays of Northern Europe, the moldboard plow was vastly superior, improving drainage and killing deep-rooted weeds, turning them from competition into compost.

The tally sticks became a kind of money—and a particularly instructive kind of money, too, because the tally stick shows us clearly what money really is: it’s debt; a particular kind of debt, one that can be traded freely, circulating from person to person until it is utterly separated from Bishop Basset and a farm in Wycombe. It’s a spontaneous tr