What investment gurus get wrong

FINANCIAL ADVICE was once doled out solely by well-paid professionals, and solely to the wealthy. Then, from the 1980s, celebrity advisers took their tips to large radio and TV audiences, especially in America. Today legions of social-media “finfluencers” spout off recommendations to anyone, anywhere. As in previous decades, the recommendations investment gurus—how to cut expenses, build a savings fund or avoid scams—are sensible and universal. Beyond the shared basics, though, their counsel differs in telling ways. They may not know it, but they hold up a mirror to their countries’ financial mores, pushing back against audiences’ vices or accidentally reinforcing them.