The Rebound Effect - counterintuitive but convincing

The controversy surrounding the validity of the rebound effect arises from a dissonance of terminology and flawed concepts about what the pertinent units of measurement are.

Proponents and opponents of the rebound effect are analyzing different variables -- opponents are analyzing a simple input/output ratio, while proponents attempt to capture the amount of consumption.

That is, opponents are interested in whether the increased efficiency enables the production of greater output (or value) with the same (or less) input.

Proponents are interested in a metric that is more difficult to define and measure -- namely the difference in resource consumption that is engendered by the increase in efficiency compared to what it would have been had efficiency not increased. It is clear that this metric is not strictly mathematical.

During the last 40 years, the efficiency of automobile engines has doubled, such that whereas in 1971 a given unit of input (gas) enabled to car to travel x miles, the increased engine efficiency enabled the same car to travel 2x miles in 2011. Or, the increased engine efficiency enables a car that is much heavier and drives twice as fast to go the same distance as a 1971 car that was considerably lighter and not as fast.

The rebound effect does not challenge the notion that engines have indeed doubled in efficiency. The rebound effect merely states that the purchasing power that is saved as a result of greater efficiency (whether by the consumer or the producer) will be applied toward the purchase of another product, thereby losing any gains made by efficiency.

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The three pillars of energy conservation:

1. Reduce Demand
2. Eliminate Waste
3. Maximize Efficiency