J. M. Smucker raising its prices in the wake of US tariffs raises an alarm. The custodian of Folgers, Dunkin’ and Café Bustelo has long been a bellwether for America’s coffee market. But are tariffs the cause, or the final straw for a market already in decline? Smucker’s US retail coffee profits plunged 22% last quarter, as tariffs on Brazilian coffee increased input costs. Volumes fell 2% as net pricing went up 18%, signalling that households are cutting back. Tariffs could accelerate...