KIYOSHI KIMURA does not like to lose. For the past six years, he has outbid all comers for the first tuna of the year sold by Tokyo’s famed Tsukiji fish market. The crown does not come cheaply. Last week, Mr Kimura, who owns a chain of sushi shops and styles himself the “King of Tuna”, paid ¥74.2m ($636,000) to win the first bluefin tuna of the year. The price nets out at some $3,000 per kilogram. Even the choicest fillets sold in markets are 80 times cheaper.

Folk wisdom holds the high auction price as a sign of increased optimism and proxy for economic buoyancy. Mr Kimura has said that he pays the exorbitant prices to “encourage Japan”. But that rationale seems fishy.

After a rival Hong Kong bidder baited him, Mr Kimura paid three times as much for the Tsukiji tuna in 2013 as in the previous year—a record-high ¥155.4m ($1.3m). GDP growth did not scale so rapidly, however, sinking from 1.7% in 2012 to 1.4% in 2013. In fact, Japan’s economic fortunes and Tokyo’s season-opening tuna prices seem to float rather erratically. A deep dive by The Economist suggests that tuna prices only explain 6% of the fluctuation in GDP, proving the relationship to be a red herring.

Environmentalists, meanwhile, are gutted. Bluefin tuna are endangered; their stocks have plunged 97% from their peak according to one estimate. The annual Tsukiji auction never fails to spawn dissent.

Still, sushi lovers remain hooked. Roughly 80% of all bluefin fished is eaten in Japan. A single piece of o-toro, the fattiest of bluefin slices, can be sold to finicky buyers for as much as $24. To break even, Mr Kimura would need to bring in $85 a piece, but they go for just $3.40 in his stores. It would seem that he is getting a raw deal.

—FIN—