It was an epoch-defining decision to place in Westminster Abbey, among statues of monarchs, priests and poets, a large one of James Watt, inventor of the separate-condenser steam engine. The statue’s inscription says Watt ranks among the world’s benefactors because he “increased the power of Man.” The economist and historian Deirdre McCloskey believes that this honor, conferred in 1834 , signified society’s endorsement of the dignity of practical people who apply science for human betterment.

The Great Enrichment is McCloskey’s term for what, in a sense, started with steam and has been, she believes, the most important human development since the invention of agriculture 10,000 years ago. The development is the explosion of economic growth that began around 1800 and has, especially since reaching China and India, lifted billions of people from poverty. Today, however, the Great Enrichment might be running out of steam in the United States, which for two centuries has given propulsive energy to it.

In 1800, McCloskey says, the world’s economy was where Bangladesh’s economy now is, with no expectation of change. Today, most of the jobs that existed just a century ago are gone. And we are delighted that this protracted disruption occurred. Now, however, the Great Enrichment is being superseded by the Great Flinch, a recoil against the frictions and uncertainties — the permanent revolution — of economic dynamism. If this continues, the consequences, from increased distributional conflicts to decreased social mobility, are going to be unpleasant.