The Globe and Mail reports in its Saturday, Oct. 3, edition that the enthusiasm for artificial intelligence is premised on the claim that the technology will so transform economic productivity that the economy will take off. The Globe's John Rapley writes that the current boom, however, appears fragile. Analysts find that to justify the hyperscalers' share prices, future earnings must increase 45 times in six years, which exceeds current growth rates. Additionally, today's double-digit growth rates are likely inflated. Hyperscaler revenues are big, sure, but only keeping pace with their equally big expenditure. They don't reflect the sort of increase in margins one would expect if profits were getting a boost from productivity gains -- in other words, they're making money because they're spending money. As for the productivity transformation AI will produce? As with Godot, there is endless talk but it never appears. In fact, what modest productivity increase we have seen in the U.S. economy has come mainly from firms that have not adopted AI, while one recent survey of firms that have done so found that "almost every report at a company about 'massive AI productivity gains' is untrue."