Most large publishers offer professors a fee for reviewing a textbook — and it's a genuine exchange, with no requirement that the text be adopted. The fees are usually in the range of several hundred dollars, and while there may not be any quid pro quo, there is the hope that in examining the text more closely for the purpose of a review, the professor will be inclined to seriously consider it for adoption.
Thus, while publishers may not be paying for the purpose of adoption, they are paying to be put on the short list of texts that are considered. Professors can't read every likely candidate for a text to use in their classes — only a few will be given serious appraisal. Since the professor is reading the text for a review anyway, it automatically falls into that exclusive club. Naturally professors who do this know that this is the purpose of the payment — they aren't that naive — but they accept the money anyway, telling themselves that since they are producing something for the money, it's ethically justified.
But in reality it's not. Perhaps it isn't quite so abhorrent as taking a bribe to adopt a text, but these professors are accepting cash in exchange for considering a book that may not be anywhere as good as other candidates that now won't have a chance. This of course means that the students lose out — and if the students' education suffers because a professor was offered money to look the other way, that's an ethical lapse for which there is no real excuse.
Then there are the cases where a professor assigns students a text she herself has written. Naturally she receives a royalty for every copy sold, so she profits directly from assigning that text. Granted, it may well be that this is the best text to use — or, even if it isn't, it's forgivable that she thinks it is. But the appearance of a conflict of interest is unavoidable.
In some places where this occurs, the professor calculates the royalties that will be received and then donates that money to charity. This may not excuse the practice entirely, but at the very least it removes the suspicion that she assigned the text out of a purely pecuniary motives. Sometimes, though, entire departments get involved — and there the motivations really do appear to be greed, greed, and more greed.
Some publishers offer to "customize" a text especially for a particular course in a particular department. They pull material from their catalogs and create a new unique text; in the process, the department is offered the chance to add their own material written by faculty members. If they do, no matter how little, they are able to make royalties on every copy sold. Thus this department profits — sometimes heavily — without there being any indication that the book in question really is the best possible text for that class.
Unfortunately, this sort of thing seems to be a growing trend in the relationship between professors and publishers. Even now there are professors who shop around, seeing which publishing house will give them the best deal on texts — not because they are looking for the lowest price for their students, but because they are looking for the largest bribe, kick-back, or royalty that they can get.
If a politician shopped around and promised to support whatever industry gave her the biggest campaign contributions, she'd be kicked out of office for bribery and probably thrown in jail. A police officer who promised to give extra protection to whatever business paid him the most cash would definitely end up in jail. Both of those are examples of an unethical abuse of power in order to profit from a position of authority. Nothing less is happening with the professors who are being paid by publishers — so why are they still allowed to retain their positions of power, authority, and trust?
