Jevons Paradox
Jevons Paradox: "Increased efficiency in resource use leads to increased, not decreased, consumption of that resource". It's tempting to believe that more efficient air conditioners must lower total electricity use, but in practice higher efficiency lowers the threshold to use them, so more people run them longer.
Origin
In 1865, 30-year-old economist William Stanley Jevons published "The Coal Question." Britain expected that James Watt's dramatically more efficient steam engine would reduce coal consumption. The opposite happened — as efficiency rose, factories, trains, and ships running on steam multiplied explosively, and Britain's coal consumption tripled by the century's end. Jevons wrote: "It is a confusion of ideas to suppose that the economical use of fuel is equivalent to diminished consumption. The very contrary is the truth."
Meaning
It's tempting to believe that more efficient air conditioners must lower total electricity use, but in practice higher efficiency lowers the threshold to use them, so more people run them longer. The same happened with LED lighting and car fuel economy. The intuition "efficiency equals savings" is only half right — efficiency lowers cost, and lowered cost raises demand. Jevons Paradox is a sober brake on technological optimism.
Lesson — Meeting Eastern Classics
Tao Te Ching 46: "No calamity is greater than not knowing contentment; no fault is greater than the desire to acquire." Laozi named the same structure 2,300 years before Jevons — efficiency does not conserve a resource; an unsatisfied appetite simply swallows back the margin efficiency created. However far technology advances, without 知足 (knowing contentment), consumption always fills the space made available.
"欲" combines valley (谷) with an open mouth (欠) — the image of a mouth open toward a ravine's rushing water, thirsting to drink it in, giving "to crave, to desire." Jevons Paradox is exactly this shape — however forcefully the stream of efficiency flows, the open ravine of 欲 swallows it whole, leaving nothing conserved.
