I do not understand what good it does them. A professor said it gives opportunity to read papers he would not read on his own. I am sure there is more to it but I do not see what they gain by participating in peer review process. It takes time, it is not paid and not even publicly acknowledged. Why do they do it?
I think academics are paid to perform peer review, in the same sense that they are paid to do research. I don't have a boss telling me what to research and paying me when it's complete; rather, my university expects me to perform research that is judged significant by my peers. In the same way, my university expects me to perform peer review. In my annual reports to the university, I report my research outputs and I report the journals for which I have performed peer review.
You may argue that my continued employment and promotion depends more heavily on my research than on peer reviewing, but the same could be said when comparing any of my service or teaching duties.
The bottom line is, academia is a gift economy, and if you want to be part of the community, you're expected to do peer review.
I can think of at least five reasons why doing peer reviews gives an advantage to yourself.
- You get to read recent research results before everybody else.
- It gives you a good opportunity to think really critically about a potentially interesting paper.
- You can put it in your CV and it will show that you are a known expert in the fields of journals you review for.
- You want to stay on good terms with the editor, who may judge your submission to the journal.
- You want to get an editorial position with the journal, which is highly prestigious. For this one typically needs reviewing experience.
The other answers do a good job of laying out the practical benefits and the roles of curiosity and obligation. However, I think there's an additional psychological factor: being asked to review a paper shows that the editor values your expertise, and that feels good. This is a shallower reason, but I think it plays a substantial role in encouraging reviewers.
I can remember the first time an editor I didn't know personally asked me to serve as a referee. It was really exciting, and I thought "Wow, this famous person has actually heard of me and is interested in my evaluation." Of course it's not as exciting the hundredth time, but it still feels good to be a valued member of the research community, and I would be unhappy if the requests stopped coming.
silvado gave a good list of “short term” answers, i.e. the reasons why one would accept a given review. Maybe I'll summarize the first two of them, because they are the ones that motivate me the most: curiosity.
Maybe curiosity killed the cat, and I'm sure it killed a bunch of scientists too, but for sure it is what makes most of us tick. Whenever I receive a request for review, even if I don't have much time for it, my first instinct is to read the abstract and think “hum, cool, how did they do it in detail?” or “I wonder if they thought about this and that” or “hey, I thought that was guaranteed not to work, how did they manage?”, or even “oh, I had never thought about that”). In all cases, it makes me want to accept.
Also, there's a long term component to it. Even though the commercial publication model is deadly sick, peer-review is a very good part of academic publication (and I mean “good” in the moral, ethical meaning). In days I am fed up with the system, I sometimes think peer-review is the only good part of academic publishing. So… by submitting papers for review, you opt in this whole peer-review system, and it becomes a moral duty to do your fair share of the reviewing work.
Don't get me wrong, you're not contractually obligated to do so. But, if you send papers for review and never accept to review any, your colleagues (and the editor) will see you as a free-rider of the system, and will resent it. And I would too.
Just to state something explicitly that was part of all the previous answers: Reviewing papers is part of being a good academic citizen.
Compared to other jobs, academia is not something you do, it's a system you enter. It's a community, an ecosystem of sorts, that provides benefits for those who are part of it, at the cost of some duties.
These duties, in academia, usually consist of publishing, teaching, supervising students, organizing and attending talks and conferences, doing some outreach, and, yes, refereeing publications, research plans, and grant proposals.
Of course, as in most communities and ecosystems, there will always be bad citizens who enjoy the benefits without the duties, and if their numbers grow too large, they end up destroying it. Fortunately though, most of us see being part of this community as a privilege and actually enjoy the extra work (see the other comments above), so that risk is, in my opinion, relatively small.
Finally, if you need an analogy, think of this site: You can ask questions and post answers. People usually do both, and actually more of the latter. You yourself invest your time in answering questions and, as an implicit trade, can rely on others to answer when the question is yours.
In addition to the other excellent posts here, I find that reading a manuscript in order to write a review is different than reading a published article just to see what is in there. When you write a review, it forces you to actually think about the manuscript, about its internal logic, about possible weak points. After all, it have heard it said that "the job of reviewers is to kill bad papers and to make good papers even better", and to make a good paper even better, you first need to understand it and think about the subject matter in a way that not even the authors did.
I find that I learn a lot more from papers I review than from other papers I consume.
When I asked the same question, the answer was "control and public relations". While the second one is obvious, the first is a little more subtle and evil. Having someone's else paper in advance it allows you to:
- establish a "give and take" relationship with peers you want on your side. anonymity is easy to break, if you want to and know what is going on in other researchers' offices.
- slow down the publication of a peer by dragging the review process or demanding additional science to be performed, especially if they are scooping you.
- get a sniff of what's going on in someone's else plate, thus granting you a head start that might be useful if you want to attack the same field.
- indirectly control the quality of a journal to reduce its score. In some universities, the current score is used to evaluate the paper production of a researcher to grant him funds. If you can have an effect on the overall quality of a journal, this will reduce the total score of a researcher's past effort, and give an edge to someone else to get more funds.