Professors should not be permitted to sell textbooks they write themselves. Instructors that sell their own textbooks can cause discrepancies among students who take the same class, but are learning from different people.
A textbook that is written by the professor can hurt the ability to study with other students and study groups. If there are eight total English 101 classes, and seven of them have the same textbook, the one class that doesn’t is going to be out of touch. A teacher has the ability to change the order of chapters in their own textbooks which can cause students to learn in an order that’s not the most efficient.
Textbooks are expensive, but students have the option of purchasing used books from online sources at a discount. This option is rarely available if a teacher is requiring students to purchase their books. This is because they receive some profit when they sell their own books.
If a book is purchased used online, the instructor does not make money. A way teachers can make students buy a new book every semester is to change a few topics in the book, and call it a “new edition.”
A textbook that is written by a professional publishing company goes through many drafts, and many edits before it is released to the public. This is not guaranteed when a teacher is the author of their own book. This can lead to grammatical errors, and important facts being left of out the textbook.
History and math courses are supposed to be taught using facts. What if an instructor has a different opinion on a historical event? Or the way a math problem should be solved? When a teacher is allowed the freedom to express opinions, it can hinder the students learning outcome.
In addition, professors are susceptible to leaving out important facts. Sure, the student learned about the outcome of the civil war, but did they learn about the important people of the civil war?
Many teachers that write their own textbooks can be lacking in credentials to do so. Yes, they know much about the topic that is being taught, but do they know the proper way to write it out? Do they know the most efficient way to explain it on paper? Textbooks that aren’t written by professionals can often times be confusing and hard to follow for these reasons.
If all students learned each course from the same book, it would be much more efficient. Students could learn and study together, even if they have different teachers.