Several weeks ago I covered this exact topic. I wrote a piece about how out of control piracy was on the Android OS. Today, again, we are looking into piracy and the negative effect it has. Previously, I got a lot of comments about how the market is not available everywhere and that skews the numbers. We have a report from KeyesLabs with some new statistics.
According to Keyes data, the excuse of "The market is not available in my country" is only partly true. Customers from Nigeria, Kuwait, and the Ukraine have found ways to legally purchase apps through the Android market without the full market being available.
Keyes data also discovered that the majority of the piracy is coming from countries who have full access to the Android market. Roughly 2/3 of all of the pirated installs are coming from Spain, Italy and Australia! Not quite sure how the report showed 0% piracy in Japan. I'm not sure I believe that.
You can read Keyes original article with some additional data here.