Which paradox says efficiency gains can increase total resource consumption?

The paradox saying that efficiency gains can increase total resource consumption is the Jevons paradox.

English economist William Stanley Jevons described the idea in his 1865 book The Coal Question. He observed that improvements to steam-engine efficiency did not reduce Britain's overall coal use. Instead, cheaper and more productive steam power encouraged its adoption across more industries, expanding the market for coal.

The mechanism is broader than a single machine: efficiency lowers the resource required for each unit of useful output and can reduce the effective price of using that resource. Consumers and firms may then demand more of the service, while higher real incomes and economic growth can add further demand. The paradox occurs when this rebound exceeds the original efficiency saving.

It is often confused with an ordinary rebound effect, which merely offsets part of an expected reduction. Jevons paradox requires total consumption to rise. Its relevance to modern energy policy remains debated; efficiency may still deliver benefits, but taxes, caps, or other conservation measures can limit rebound growth.