International editions

Why are many of my textbooks marked "Internation Edition, not for sale in USA and Canada"? What would they need to change "for the benefit of students outside the United States and Canada."?
Are you guys hoarding all the good stuff for yourselves? Like "Ha, ha, we'll sell those silly Europeans a version where we cut out the proof that P=NP."

We send books to europe that assume the law of the excluded middle in logic and mathematics, which we've actually proven untrue, but we don't want them to know.

International editions are very inexpensive. If it were sold in US, Canada, people would only buy the international versions. Usually the only difference is that they are soft-cover.

Textbook companies are colluding to keep prices (and thus profits) high in the US.  Yay for conspiracy.