Simon Willison’s Weblog

One way to establish that peace-preserving threat of mutual assured destruction is to commit yourself beforehand, which helps explain why so many retailers promise to match any competitor's advertised price. Consumers view these guarantees as conducive to lower prices. But in fact offering a price-matching guarantee should make it less likely that competitors will slash prices, since they know that any cuts they make will immediately be matched. It's the retail version of the doomsday machine.

— James Surowiecki