Is there ever a definitive answer? Krystallina looks at one study for clues.

Where do you get your manga?

Hopefully, you answered something like, “At my local bookstore!” or, “At an online retailer!” or even one of the free legal resources. However, I’m sure that some people’s first instinct was a scanlation site or, in some cases, a raw manga provider. The debate over piracy has been raging for years, with companies saying that unauthorized downloads affect sales while downloaders says it provides advertising and hype. Lots of studies, statistics, and stories have been submitted over the years as proof of each side’s arguments. One recent research project comes from Professor Tatsuo Tanaka of Keio University. His paper, titled “The Effects of Internet Book Piracy: The Case of Japanese Comics”, offers a conclusion that both sides will probably cite as further proof that they are right.

The Study

Professor Tanaka’s full paper can be found here. (Yes, in case you’re wondering, it’s in English.) Here’s the tl;dr version:

From July 2015 until March 2016, most manga publishers — with some help from the Japanese government — launched an intensive campaign to delete their titles from file-sharing sites. This study looked at 322 manga titles from the Big Four of manga publishing that were targets of this takedown. An additional 162 manga were added as a comparison. E-book versions were counted separately. Four volumes from these series — some completed, some ongoing — were then analyzed by looking at the number of download links still active.


Tanaka found that free downloads of ongoing manga series did affect sales. However, pirated versions of recently completed manga actually appeared to actually help those titles. The hypothesis is that people forget about finished series since publishers aren’t promoting them. The suggestion is to have publishers focus their anti-piracy efforts on manga that are still being released instead of trying to combat all instances of illegal downloads.

Here’s page 21 of “The Effects of Internet Book Piracy: The Case of Japanese Comics” showing the displacement and remind effects:

Piracy Figures - Displacement/Remind Effect


“See! Downloads and scanlations do help!”

Well, as Tanaka points out, “An interesting question for further research is whether the total effect of piracy is negative or positive.” While the number of completed series and volumes far outnumbers the currently ongoing ones, finished manga may only sell a few hundred per month versus several thousand for the latest series. A bump in older volumes is probably not enough to offset the lost in revenue from current series. (After all, Oricon charts are not known for a lot of old classics.)

Second, this study online examined Japanese sites. It also focused on “cyber lockers” — aka file download sites. It did not look at illegal manga reader sites. Considering these types of sites are immensely popular — and arguably more convenient — Tanaka’s research may have had very different findings if English (or other non-Japanese) websites were used.

And even though completed series had a boost, the biggest impact was seen on manga that had published its final volume in between 2010 and 2013. In fact, this sales increase was not seen in manga that finished in 2014 or before 2009. Why? For the recently completed series, the hypothesis is that the manga is still pretty fresh in people’s mind. As for the older completed works, “One of the possible explanations is that consumers lost interest in the comics of that time period because the style or quality of comics had changed.” So even if someone argues that finished manga does get a boost, this study suggests that sales will still be lowered for at least a year after its completion. A year may not seem like a long time, but with so many new manga coming out each year (not to mention new anime that sparks interest in its source material), companies are losing out on prime marketing time before it “ages out” and loses any sort of promotional push from the publisher.

Final Thoughts

It is always interesting to read about actual research and not claims. I think Professor Tanaka’s findings are not too surprising. A lot of people may have started a series, forgot about it, and then use piracy to catch up and decide if it’s worth continuing again. Other readers may go back and look at an author’s previously finished work. In addition, if someone had interest in a series that had just finished, then there’s a high chance probably downloaded the volumes as it was coming out. This would explain why series completed in the last year did not see an increase in sales.

However, most manga profits come from current series. Even if you believe that loss in revenue for ongoing series is made up by boosted profits in older series, you can’t expect creators to wait a few years after their work is done to get their full royalties.

So, what do you think of this study? Are Professor Tanaka’s findings what you would expect, or did the results surprise you?