The promise of generative AI technology to transform companies, industries, and societies is leading tech giants and beyond to spend an estimated ~$1tn on capex in coming years, including significant investments in data centers, chips, other AI infrastructure, and the power grid. But this spending has little to show for it so far. Whether this large spend will ever pay off in terms of AI benefits and returns, and the implications for economies, companies, and markets if it does—or if it doesn’t—...