CHICAGO – With the world’s industrial democracies in crisis, two competing narratives of its sources – and appropriate remedies – are emerging. The first, better-known diagnosis is that demand has collapsed because of high debt accumulated prior to the crisis. Households (and countries) that were most prone to spend cannot borrow any more. To revive growth, others must be encouraged to spend – governments that can still borrow should run larger deficits, and rock-bottom interest rates should discourage thrifty households from saving.