All kinds of bank and nonbank lenders are heaping credit on household balance sheets even though the consumer economy is fragile: A tiny minority that can afford luxury goods is in great financial shape, but low-income earners, especially outside large cities, are struggling with two-wheeler purchases and smartphone upgrades. Lenders know they have to make the most of this uneven K-shaped recovery, especially if the current crisis in US banking snowballs into something sinister.