Our global economy would stupefy a Roman merchant as much as the Roman economy would have confounded a caveman. But we would be sim- ilarly amazed to see the economy that awaits our grandchildren, for I expect it to follow a societal discontinuity more dramatic than those brought on by the agricultural and industrial revolutions. The key, of course, is technology. A revolutionary speedup in economic growth requires an unprecedented and remarkable enabling tool. Machine intelli- gence on a human level, if not higher, would do nicely. Its arrival could produce a singularity—an overwhelming departure from prior trends, with uneven and dizzyingly rapid change thereafter. A future shock to end future shocks.