English: The price of lighting has fallen by more than 99.9% since 1300

Economic historians have reconstructed the price of light over the very long run for the United Kingdom. This data shows that the price of lighting has plummeted in recent centuries.

If we look at long-run datasets on the price of lighting in the UK, we see that prices fell by more than 99.9% from 1300 to the early 2000s.

In the 1300s, one million units of lighting — a lumen-hour — would have cost around £40,800 in 2000 prices. By 2006, this had fallen to £2.90. That is a 14,000-fold decline.

This reduction in prices has transformed the availability of light across the world.

WHAT YOU SHOULD KNOW ABOUT THIS DATA This data is sourced from the study by Roger Fouquet and Peter Pearson.1 To calculate the price of lighting – today or historically – three different prices need to be known: (1) the prices of the relevant energy source, (2) the equipment to provide this light (e.g. a kerosene lamp), (3) how efficiently the available technology at the time can turn the energy into light. The latter is referred to as the ‘lighting technology efficiency’ in the literature and is measured in units of energy used for each lumen-hour of light generated. The authors adjust these prices for inflation over time; the full series is measured in prices of the year 2000.

Prices are weighted from the combination of lighting sources at any given period of time. For example, prices of lighting from candles, whale oil, and gas will differ. The average price is, therefore, weighted by the share of each source in total lighting consumption.