In 1865, the economist William Stanley Jevons noted a counter-intuitive fact: steam engines that burned less coal had not reduced coal consumption, they had increased it. His lesson: making the use of a resource more efficient does not necessarily reduce its total consumption. It can even push it up. That is the Jevons paradox, and its engine is called the rebound effect.
1 What are we talking about?
A false intuition, a true paradox.
Definition
The efficiency that feeds demand
The Jevons paradox arises when a technical advance, by making the use of a resource more efficient, lowers its effective cost, and when that drop in cost stimulates demand so much that total consumption rises instead of falling. The more efficient it is, and therefore the cheaper to use, the more it is used. Efficiency per unit improves; the number of units improves more.
2 The rebound effect
Measuring the gain taken back.
The mechanism
What efficiency gives back, use takes back
The rebound effect measures the share of the expected savings that is "taken back" by the rise in use. Picture a device twice as efficient: in theory, it should consume half as much. But because it is cheaper to run, it is used more, and the real saving falls short of the promise. As long as the rebound stays below 100%, efficiency still reduces consumption. That is the most common case.
3 When it kicks in
Three conditions, all met.
The ingredients of the paradox
①
An efficiency gain that genuinely lowers the cost of using the resource.
②
A highly elastic demand: price-sensitive, so that the lower cost sharply raises the quantities demanded.
③
A market far from saturation: a vast latent demand remains to be unlocked. Where demand is fixed (eating, for instance), the paradox does not apply.
4 Rebound or backfire
Everything turns on a threshold.
The 100% threshold
When the rebound exceeds 100%, it is called "backfire": total consumption rises because of efficiency, not despite it. That is the Jevons paradox in its purest form. At the level of a single device, the rebound rarely exceeds 100%. Across a whole economy, it is more frequent, but also harder to prove. The practical implication is clear: for efficiency to genuinely cut consumption, a safeguard that keeps the cost of use up is often needed, such as a tax or a cap.
5 Takeaways
To remember.
✓
Jevons paradox: making a resource more efficient can raise its total consumption.
✓
The rebound effect measures the share of the savings taken back by the rise in use.
✓
Beyond 100% rebound ("backfire"), total consumption rises. Without a cap, efficiency is not enough.
This notion sheds light on an analysis
First published: 21 June 2026