It's possible that by reducing traditional workplace hazards and making all work less strenuous, Americans have increased the risk from obesity, which is related to a sedentary life. About a year ago, the economists Darius Lakdawalla and Tomas Philipson, in a different paper for the economic research bureau, asserted that less strenuous work and cheaper food — both products of technology — are to blame for the rise of obesity in America.

Both papers imply that the epidemic of fat — three in five Americans are overweight — is what Edward Tenner, author of "Why Things Bite Back: Technology and the Revenge of Unintended Consequences" (Vintage Books, 1997) might have called a "revenge effect." It is the kind of unintended consequence that often flows from new technologies and social change.

Obesity arising from more (and safer) work is a dispiriting manifestation of this syndrome, but Dr. Chou, Dr. Grossman and Dr. Saffer have come up with an even nastier one: the war on cigarettes, they observe, is making people fatter, too, simply because smoking, however harmful, causes people to eat less.
—Daniel Akst, "Belt-Loosening in the Work Force," The New York Times, March 2, 2003

The myth that computers would allow us almost unlimited leisure time was closely related to the myth of the paperless office. The reality is that, thanks to ubiquitous fax machines, photocopiers and computer printers, offices now use more paper than ever before. Other modern revenge effects include high-tech sports safety equipment that can increase the number of severe injuries, low-tar cigarettes that make you smoke more and antibiotics that can breed new and more virulent bacteria.
—Craig Webster, "Technology's revenge," The New Scientist, August 14, 1999

Why do the seats get smaller as the airplanes get larger? Why does voice mail seem to double the time to complete a telephone call? Why do filter-tip cigarettes often fail to reduce nicotine intake? Why has the leisure society gone the way of the leisure suit?

The world seems to be getting even with mankind, twisting our cleverness against us. Or we may be unconsciously twisting it ourselves. This is not a new phenomenon, but technology has magnified it. Wherever we look we face unintended consequences of mechanical, chemical, medical, social and financial ingenuity. They are revenge effects, and they are less the malignant ironies of a spiteful world than the results of a lack of human foresight.
—Edward Tenner, "Voice mail and fire ants," The New York Times, July 26, 1991