How many man hours to turn on a lightbulb and why should investors care?

This post is also available in: frFrançais

Technological progress can have surprising consequences. Take the cost of producing light, for example.

The environmental economists Roger Fouquet and Peter Pearson have retraced this development in England. One hour of light (referred to as the quantity of light shed by a 100-watt bulb in one hour) cost 3,200 times as much in 1800 in England as it does today, amounting to just over 150 of today’s US dollars. In 1900, it still cost around 5 dollars. By 2000 the cost was 5 US cents.

This technological advance can also be thought of in terms of the amount of time an average worker needed to labour in order to earn enough for the 100-watt bulb to glow for an hour. In 1750 BC, the people of Babylon used sesame oil to light the lamps, and had to work for 400 hours to produce the said amount of light. In around 1800, using tallow  candles, 50 hours of work was required. Using a gas lamp in the late 19th century, three hours were necessary. Using an energy-saving bulb today, you will have to work for the blink of an eye – a second. This amounts to a phenomenal advance in productivity and thus prosperity.

Over recent decades, the combination of a larger pool of global labour, transformative technologies and the expansion of global value chains has led to a massive supply shock that has generated a wave of ‘good’ disinflation which advances prosperity for the world’s population as a whole.

Brendan Mulhern – Newton, a BNY Mellon company

  • Download
  • Print
Comments are closed.