Why do math/physics professors publish textbooks?

Question

Does it help their tenure case to write an expository textbook? I'd be surprised if it does, seeing as writing a textbook on, say, quantum mechanics, is not original scholarly work.

So why would a professor, say an aspiring full professor, write a textbook? Money?

Answer 1

Does it help their tenure case to write an expository textbook?

While I cannot speak for math or physics, in many of the biological and medical sciences, it would likely actively hurt your tenure case. "Why did you spend your time writing a book instead of getting more grants/writing more papers?"

So why would a professor, say an aspiring full professor, write a textbook?

There are a few reasons one might be interested in writing a textbook:

• You have, effectively, already written one. Many professors, having taught a course for a number of years, have accumulated a body of lecture notes, slide figures, exam questions, etc. that might be the foundation for a decent text on the subject. Writing a book is a way to get "credit" for all that.
• There is no book on the subject you're writing, and you want one.
• Writing a well-regarded textbook is a means to influence the direction of the field. For example, if you wanted to push a particular perspective on how one should approach the field, etc. writing a textbook on the topic is a way to do that. Again, not in math/physics, but in my field people are writing textbooks with either a causal inference or systems science bent to them to try to help push those methods forward.
• Simple desire. Books are neat. They feel important. Many people are rather fond of them as objects. Seeing your name, and your thoughts, in a proper book on a shelf is an appealing concept. That may be enough.

Answer 2

It's probably not for money, at upper-division or graduate level, because one will not make much. Better to work part-time at a fast-food place or coffee shop. Also, not much "prestige" of any sort. And, no, does not count toward getting tenure (and may count against, subliminally).

The real reason (I think, certainly in my own direct experience) is that one simply can't help oneself. This ought not be entirely surprising, since, after all, most people who go into academic mathematics do not do so because the contemporary commodified form of universities and mathematics exactly suits them, but because they like engagement with mathematics, perhaps to the degree that they can mostly overlook the artificial rules.

So, yes, after teaching various versions of a course several times, one may easily discover that many of the traditional textbooks have at least one failing, namely, that they attempt to include too much, to avoid alienating anyone who'd be alienated by omission of their pet topic. Or, oppositely, stay too elementary, to avoid alienating another demographic.

So, yes, one might choose to compose course notes for the courses one teaches, to match one's notion of what those courses should be. No, it is not for external reward, but almost entirely so that one does not have to "battle" with the "recommended text(s)". (Especially before it was possible to easily typeset mathematics, I experienced many episodes of students being unwilling to believe the palpable mathematical truth of what I was telling them, because the recommended text either omitted the topic or had "different definitions". It was annoying.)

Another point is to make a coherent account freely available... which is somewhat orthogonal to creation of traditional textbooks, which are still mostly not freely available. However, some publishers (e.g., Cambridge Univ Press) are happy to negotiate details.

And, last, although writing "books" has very little cachet for most purposes, having notes approved by a conventional publisher is slightly higher-status than having no vetting at all. It shows external approval, etc.

EDIT: also, although "by the rules", a textbook is not "original scholarly work", in fact, it easily can be. That is, in addition to the non-trivial questions of what to include, what to omit, and how to treat the things, there is a subtler (possibly not-so-quantifiable... for the current impact-factor sort of ... noise) manifestation of expert-tone, expert-appraisal, and such. So, yes, it is possible to write textbooks that are not at all scholarly, beyond a modestly competent collecting of well-known standard things. At the same time, it is possible to do better, and, to do better requires considerable expertise and judgement, apart from the logistics, and should be (and mostly is, but off-the-record) respected.

Answer 3

Because textbooks are still "evolving". A good new textbook has a lot to offer. It might not be original work, but it might be even better than that! It could be better than the previous books on the subject. How many times have you caught yourself reading a textbook and thinking, "This layout is horrible!" or "I could explain this better" or "I wish someone could illustrate this in a better way". Not to mention the amount of mistakes one can find in most textbooks.

I imagine there are a lot of professors that want to do just that and improve the quality of the books and make sure that knowledge will be passed on to the next generation of students in a better way.

It could always be about money... then again, an "aspiring full professor" is unlikely to have that motive in mind.

Answer 4

While the content of a textbook may not contain much in the way of new research, the organization and expression of that content can be a highly creative act. People write textbooks for the same reason they write poetry or short stories (or sculpt, or play music...): it's an act of creative expression, which is intrinsically satisfying.