Mokyr’s larger thesis is that technology is the most important driving engine of growth. It’s not the only factor, but the most important one–and it isn’t the direct factor. Lurking one level beneath technology are cultural attitudes about technology and progress. This, to Mokyr, is where the real explanation lies for the origins of the modern economy. The Romans had the technology for the steam engine. But Roman culture wasn’t interested in applying technology to improving production processes the way the 18th-century Britain was when James Watt was a young man. So steam power remained a novelty toy for the wealthy, and was soon forgotten.
Technophobic and neophobic cultures tend to have less technological progress. As such, they tend to be less prosperous and grow more slowly—and even then, much of the growth is “catch-up growth” when technologies long established elsewhere reluctantly enter through osmosis. There is a good deal of intersection here with Deirdre McCloskey’s work, which focuses more on wider bourgeois values. But Mokyr confines himself for the most part to technological norms rather than wider arguments about attitudes about letting people have a go, whether through commerce or life’s many other worthwhile aspects.
Mokyr has written several books applying his technology-and-culture thesis to different historical periods. His thinking has evolved over time, though the general framework has proved sturdy enough to pass the test of time. A Culture of Growth focuses mostly on Europe from 1500-1700, from roughly the end of the Renaissance, through the Scientific Revolution, up to the Enlightenment’s earliest stirrings. Essentially, these two centuries laid the cultural ground the Industrial Revolution needed before it could stand on its own.
See also Pierre Lemieux’s review, which goes into much more detail than this one.