In 1963, the year his company bought a nine-store chain then known by the two-word name Radio Shack, Charles D. Tandy explained to the New York Times why it made perfect sense for a retailer of do-it-yourself leather handicrafts to buy an electronics distributor.

“Leisure time is opening markets to us,” he told the Times. “The shorter workweek, human curiosity, idle hands—all offer opportunities in this business. Everyone’s spare time is our challenge.”

What Mr. Tandy couldn’t know was that the real challenge his company would eventually face was the slow erosion of the very leisure time his company profited from by filling. The company, now known as RadioShack , filed for bankruptcy protection last week.

It’s hard to believe this now, but according to “The Overworked American,” by Boston College professor of sociology Juliet Schor, in the 1950s the shrinking workweek meant universities sprouted departments of leisure studies, to figure out what Americans would soon be doing with their ever-expanding supply of free time.

Then, in about 1970, the trend reversed, and the workweek of the average American began to grow longer.