Ask Mr. Know-It-All: Why do all films in Hong Kong have subtitles?

Dear Mr. Know-It-All,
Why do all films in Hong Kong have subtitles? It’s really distracting! –Sub Terranean
There’s a popular legend which says the British Government passed a law in the 1960s, mandating that all films produced in Hong Kong had to be subtitled in English. That way colonial officials could easily keep an eye on any attempted sedition and stop the wrong messages from getting out. It was all part of maintaining a grip on a colony which was beginning to display some uneasiness with life under British rule.
It’s a great story. But in fact there was never any such law. The reasons behind Hong Kong’s bilingual subtitling system are much more prosaic: It’s all about the money.
The 1960s was the heyday of the Shaw Brothers Studio in Hong Kong. Movie mogul Run Run Shaw pioneered Hong Kong cinema, cranking out classic film after classic film, defining in particular the look and feel of kung fu flicks for generations to come.
But Shaw’s audience was never just Hongkongers. He owned cinema chains spread over Southeast Asia, and distributed his films straight to the Chinese populations of Singapore, Malaysia and more. But there was no single language that would cater to this Chinese diaspora, who all spoke different dialects of the language. So Shaw standardized his films in Putonghua, reasoning that it was the most universal dialect around. The fact that Shaw had snapped up some of China’s finest filmmaking talent as it filtered south to Hong Kong in the 1960s probably didn’t hurt, either.
Putonghua vocals made sense, but you couldn’t guarantee everyone would understand it—you still can’t, in Hong Kong. However, dubbing is costly, especially if you have to produce multiple tracks for multiple dialects. The easy solution presented itself: subtitles. It didn’t matter if you spoke Cantonese, Hakka or Hoklo: you could read the standardized Chinese subtitles and get the plot.
But the films were being made in British-ruled Hong Kong—so why not throw in English subtitles, too? That way you could show them to interested colonial types as well as export them to the United States. Chinese subtitles broadened the market for your films across Asia; bilingual subtitles widened your reach across the world.