In 1865, in The Coal Question, the economist William Stanley Jevons noticed something counterintuitive: steam engines had become much more efficient in their use of coal, yet coal consumption in England went up.
Efficiency makes each use cheaper, and the lower price makes viable uses that weren’t worth it before. If demand grows faster than the savings per use, the total goes up.
Everyday tech examples:
- Storage and bandwidth: they got orders of magnitude cheaper, and today we store and transmit orders of magnitude more data.
- AI: every drop in cost per token opens new use cases (classifying every email, reviewing every tool call). It is the bet behind the name of JEV.
The effect is not guaranteed: it depends on how much demand reacts to price. When the reaction is small, efficiency does reduce consumption.
- To dig deeper: Jevons paradox (Wikipedia)