Tragedy of the Commons

A single Pacific Blue fin tuna sold for 3.1 million US dollars at the Toyo Sioux Market in Tokyo on the 5th of January 2019. The buyer was Kyoshi Kimura, the owner of the Sushizan Mai restaurant chain. The fish weighed 278 kg. What the headlines did not show was that the Pacific Bluefin population had collapsed by more than 96% from its historical peak. The collapse had a clean explanation. Bluefin tuna were a shared ocean resource. No single sushi restaurant, no single fishing boat and no single country owned them. The boat that did not catch the tuna would simply watch a competitor catch it instead. The rational thing for each individual fisher was to take the fish. The result was the tragedy hidden in every individually rational decision.