Starbucks’s New CEO Will Need to Be a Quick Study

The prospect of union drives at its thousands of US coffee shops may be the most visible challenge facing Laxman Narasimhan when he takes over the world’s largest coffee chain on April 1, but it’s hardly the only one. A global economic slowdown, shipping disruptions and coffee price fluctuations are among the uncertainties sure to be front and center for the new chief executive officer—especially since Starbucks Corp. founder Howard Schultz, who’s twice returned from retirement to replace earlier successors who faltered, will remain on the board to keep an eye on the transition.

“The restaurant industry is facing ...