Just three days ago, I wrote about the increasing number of authoritative voices warning about signs of an AI-related stock market bubble. As is always the case with financial markets, there is another body of opinion that says that the pessimism is unwarranted. How then do mere mortals like me make sense of this complicated picture? I expressed hope in my article that at least one of the visionary leaders of the AI industry would volunteer to offer an insider’s viewpoint. But I also thought that there was zero chance of such a thing occurring.

I was quite pleasantly surprised therefore to see the unexpected happen. In a wide-ranging interview with the BBC yesterday, Sundar Pichai, the CEO of Alphabet, the parent company of Google, said that ‘while the growth of artificial intelligence (AI) investment had been an “extraordinary moment”, there was some “irrationality” in the current AI boom.’ Asked whether his company could emerge unscathed from a bursting of an AI bubble, Mr. Pichai replied: “I think no company is going to be immune, including us.”

Mr. Pichai did affirm the extraordinary potential of AI, calling it “the most profound technology” ever worked on by humankind. He indicated that Alphabet will continue to invest heavily to compete with Nvidia and the other leading companies in the AI space. That is clearly a vote of confidence in the industry, which should offer useful guidance to investors. But his caution deserves greater attention.

It is the view of many economists that the bursting of an AI bubble would most likely cause a global recession. By suggesting that some of the sky-high valuations of AI company stocks may not be justified, Mr. Pichai has done us all a tremendous service. Sometimes we need voices like his to save us from ourselves.