Janet Albrechtsen summarizes Matt Ridley's argument:
On an average wage today, half a second of work will pay for an hour of light. In 1950, the average wage earner worked eight seconds to run a conventional filament lamp; in 1880, 15 seconds of work was needed for a kerosene lamp; and more than six hours of work for an hour of light by tallow candle in the 1800s. In 1750BC, your average ancient Babylonian needed to work more than 50 hours to get an hour of light from a sesame oil lamp. That 43,200-fold improvement, says Ridley, signifies "the currency that counts, your time."
(Hat tip: Kirstin Butler)
The Dish 