It is not Beyoncé Knowles or Britney Spears, but Ayumi Hamasaki of Japan.

In central Hong Kong, buses carry huge posters of the J-pop starlet Namie Amuro and boy bands like Smap. In Ho Chi Minh City, markets bombard shoppers with posters of acts like Glay and Soulhead. Pirated versions of animated Japanese films are huge sellers from Bangkok to Seoul. Ditto for “manga” comic books.

The sudden ubiquity of Japanese culture isn’t just an Asian phenomenon. Sushi has transcended fish-bait jokes and now gets served at sporting events in the United States. Children in Miami, Rome and Sydney ask mom and dad for Hello Kitty, Doraemon or copies of “Spirited Away.” New York’s fashion aficionados increasingly buy the designs of Jun Takahashi and the Bathing Ape label.

All this gets at a trend about which economists are getting excited: The increasing export of Japanese culture. If Japan’s gross national product is getting you down, try its “gross national cool” on for size.