The economics of hand signals
Before dawn, while Tokyo sleeps, an intense economic ritual begins. On the green floor of the Toyosu Market, hundreds of frozen bluefin tuna are laid out in precise rows. Each fish, a potential transaction worth thousands, or even millions, of dollars, is inspected by licensed buyers. They use flashlights to check the color and texture of the meat from a small cut near the tail. At 5:30 AM, a bell rings, and the auctions start. Auctioneers begin a high-speed chant, and a flurry of hand signals—a system known as teyari—fills the air. Each flicker of a finger bids a bid, a complex language conveying prices in seconds.
This silent, rapid negotiation is a real-world example of a repeated game. The bidders, mostly intermediate wholesalers representing restaurants and retailers, interact daily. In game theory, this repetition changes behavior. Instead of engaging in aggressive bidding wars that would drive prices unpredictably high and erode profits, the bidders use the teyari system to engage in a form of tacit collusion. They signal their intentions and price levels subtly, maintaining a stable market without explicit agreements. This behavior allows them to manage competition and secure the fish they need at predictable costs, ensuring their own business stability. Each sale of a bluefin, sometimes sold in mere seconds, demonstrates this unspoken economic equilibrium.
From Tsukiji to Toyosu
The famous tuna auction was part of the Tsukiji Market, which opened in 1935 after the Great Kanto Earthquake of 1923 destroyed the city's previous fish market in Nihonbashi. For over 80 years, Tsukiji was the world's largest fish market, a sprawling and chaotic market. In October 2018, the inner market and its wholesale operations, including the tuna auction, moved to the modern, climate-controlled Toyosu Market. The old Tsukiji Outer Market, with its many restaurants and shops, is a popular destination.
The move to Toyosu changed the viewing experience. At Tsukiji, a limited number of tourists could stand near the action on a first-come, first-served basis, often queuing from 2:00 AM. At Toyosu, visitors watch from behind glass on an observation deck. A special lower-level deck, closer to the auction floor, offers a more direct view and sound, but access is limited to about 100 people per day, granted through a monthly lottery. Despite the new, more sterile environment, the core economic drama of the auction continues. The market still sees around 200 fresh and 1,000 frozen tuna auctioned daily.