The big bet on AI—the near-trillion dollars that hyperscalers are spending to build out the technology’s infrastructure—is predicated on the belief that productivity will skyrocket. If that bet pays off, a new report from policy research center Yale Budget Lab finds AI could help tackle one of the country’s most urgent crises: the $39 trillion national debt. The report offers a scenario on how AI could trim down the country’s piling debt, but co…