On January 15, 1925, executives from the world’s largest light bulb makers met in Geneva and stopped competing. Osram, Philips, Tungsram, Associated Electrical Industries, and General Electric incorporated a Swiss entity called the Phoebus cartel, divided the world’s markets, and pooled their patents. Then they turned to the bulb itself. A standard incandescent lamp lasted about 2,500 hours. The cartel ordered that it fail at 1,000.

This episode works through the documents behind one of the best recorded cases of planned obsolescence. Members had to send sample bulbs to testing labs in Switzerland, and any company whose lamps burned too long paid fines in Swiss francs on a sliding scale. The story also weighs the defense: a thinner tungsten filament burns brighter and more efficiently, and British investigators later called 1,000 hours a sound engineering compromise. The answer offered here is that the physics was real, and the cartel used it to remove the customer’s choice.

• Anton Philips warned a fellow member that lax control of factory voltages could send them sliding back into the mire of supplying long lasting lamps.
• Shares in the Swiss corporation were distributed according to each member’s global lamp sales, and General Electric had already used a front company in Paris to enter Europe.
• In 1949 a U.S. district court in New Jersey found General Electric guilty under the Sherman Antitrust Act, ruling the 1,000 hour limit was driven by profit.
• In 1951 the UK Monopolies and Restrictive Practices Commission told Parliament that 1,000 hours balanced brightness, electricity use, and lifespan.
• The agreement was written to run 30 years, until 1955, but World War II broke it apart. Thomas Pynchon’s 1973 novel Gravity’s Rainbow, with its immortal Byron the Bulb, brought the cartel back to public attention.