[kipchak]

The statement by UK Monopoly and Restrictive Practices Commission seems to be inaccurate as the objective was an average lifespan of 1,000 hours, not "on average a minimum life of 1,000 hours" as bulbs that exceeded 1,000 hours were fined, as well as those lasting less.[1] That bulbs lasting longer than 1,000 hours were fined, regardless of their wattage used to lumens produced seems explainable only by a desire to restrict lifespans, and contrary to efficiency or minimum lifespans being the goal.

From [1], quoting Anton Phillips discussing members building higher voltage and longer lived bulbs,

“This, you will agree with me, is a very dangerous practice and is having a most detrimental influence on the total turnover of the Phoebus Parties…. After the very strenuous efforts we made to emerge from a period of long life lamps, it is of the greatest importance that we do not sink back into the same mire by paying no attention to voltages and supplying lamps that will have a very prolonged life.”

[1]https://spectrum.ieee.org/the-great-lightbulb-conspiracy