Wright's Law
Why costs fall a fixed percentage with every doubling of output.
Wright's Law, named for aeronautical engineer Theodore Wright, observes that the unit cost of a manufactured good tends to fall by a roughly constant percentage for every doubling of cumulative production. It is the quantitative backbone of the abundance thesis: it is *why* technologies like solar, batteries, and sequencing get reliably cheaper, and why the Wright-curve argument treats continued cost decline as the null hypothesis rather than an optimistic forecast.
Learning by doing, measured
Originally derived from airframe manufacturing in the 1930s, the regularity has since been documented across hundreds of products. Studies comparing forecasting rules have found that Wright's Law — keyed to cumulative volume — predicts technology costs at least as well as time-based (Moore's-law-style) extrapolation. The mechanism is learning by doing: each unit produced surfaces process improvements that the next unit inherits.
The policy reading
If cost falls with cumulative volume, then deployment is itself the cheapest research program: subsidizing early demand buys down future cost for everyone. This reframes the energy transition as a question of removing frictions to installation — permitting, interconnection, finance — so the curve can keep compounding. It also warns that curves stall without continued production, not on a fixed calendar.
Sources
- Experience curve effects — Wikipedia
- How predictable is technological progress? — arXiv
- Why did renewables become so cheap so fast? — Our World in Data