[mgaunard]

Writing a PhD is much easier than writing a book.

To begin with, it has a very simple and constrained structure: abstract, problem description, state of the art, interesting subtopic 1, interesting subtopic 2, interesting subtopic 3, results and perspectives.

Interesting subtopics are also just previous articles that you can just recycle.

[jszymborski]

> Writing a PhD is much easier than writing a book.

IMHO, I think that's a pretty broad statement that's wrong as often as it's true. Surely it depends on the book, the thesis, and the discipline/genre.

Firstly, not all disciplines have theses broken down in the way you've outline. Theses in certain humanities often more resemble non-fiction than those of other disciplines.

Of course, some disciplines or departments or schools or supervisors will have you write a "thesis by manuscript" in which you present manuscripts you've written as chapter and write little interludes connecting them as well as a unifying intro and conclusion.

This on the face of it might seem like "just recycling" previous articles, but I think it overlooks the fact that those manuscripts must be written, at least in majority, by you. Even when you aren't writing a "thesis by manuscript", most people I know write chapters as they go along their PhD.

And finally, a bit of digression, but I don't think it's reasonable to exclude the amount of research it takes to write "books" or theses from the estimation of effort it takes to write them. It's an integral part of the process.