I’ve noticed that – at least in the US – a book is published and sold at a non-trivial price to US residents. However, the author/publisher may also make an international version.
This version is subpar in my opinion. For example, they are cheaper, but also typically paperback, and I’ve seen in a science textbook things such as “this problem has intentionally been omitted for this edition” and “this [foot]note has been intentionally omitted for this edition.”
Why are international editions stripped-down versions of their original counterparts? Why the need to omit certain problems and footnotes?
(I had asked this question first in Law Stack Exchange, but they deleted it and suggested I ask it here. So, any help on the legality of these reasonings would be appreciated).