A few days ago, a smart 22-year-old asked me how to invest some savings from her first job. I advised her to open an individual retirement account. When she found out she couldn’t withdraw it without penalty until she turns 59 1/2, she shot back: “By then the planet will be a rotating cinder!”

The many young people who seem to share her gloomy view of the future should read the new book by Laurence B. Siegel, “Fewer, Richer, Greener.” In it, he proclaims, “We are on the verge of the greatest democratization of wealth and well-being...