Nineteen years ago, I first came to Japan to work as an English teacher at Nova Group. On my third day of teacher training in Tokyo, I thought I'd sized up my trainer well enough to drop the U-bomb in conversation. "So what do you think of the Nova teachers union?" I asked. "I think you should join it," he replied, in his strong Yorkshire accent.

What he said next cut through all the microeconomic dogmas that dismiss trade unions as rent-seeking cartels. The union, he explained, acted as an early warning system for the company, alerting it to problems in labor practices that could otherwise progress to expensive, confrontational legal action, with all the bad publicity that implied. Perhaps Nova ultimately failed to heed the union's advice, but I have kept his wisdom in mind down the years in my own (sometimes unsuccessful) union-organizing efforts.

Of course, the primary aim of unions is to bargain for improved wages and working conditions on behalf of their membership. As manufacturing industries hollow out in postindustrial economies worldwide, and their labor markets divide between minorities of highly paid professionals and growing numbers of poorly paid, insecurely employed workers, the case for renewed union activism has never appeared stronger. However, many of the working class occupations that were once central to trade union cultures have disappeared, and the service and gig economy jobs that have often replaced them seem especially resistant to union organizing.