Should I accept authorship on large collaborations for which I have made little contribution? I have just started a post-doc. So far all of my papers have had small author lists (4-5 people). I have just been invited as a co-author on several papers with hundreds of authors. The papers are pitched as community-wide collaborations: some being white papers describing a future experiment that the community plans to engage in, others being the results from first data from such experiments. My contribution, and the contribution of 99% of the authors whose names are already there, have been negligible. What are the pros and cons of agreeing to be on such a paper?
What are the pros and cons of agreeing to be on such a paper?


Pros


Your contributions to the collaboration are formally acknowledged, both incentivizing you to continue working on it as well as putting the candle under your butt to get up to speed on anything you should be getting good at.
Leaders in the collaboration see you listed as a contributing member, allowing your candidacy for the next round of projects that need attention by working group members.  Generally, people reach out to include you going forward.
You will be put on mailings that automatically include all researchers on the paper, keeping you up to speed as developments happen in real time.
Your association with the project is beneficial to both your career (i.e., Look at this thing I worked on!) and the project itself (i.e., Look at this great contributor we have!).


Cons


None.  Literally none.


There is a related problem in academia called illegitimate co-authorship, or sometimes authorship inflation, but that is a problem to be tackled by policy.  If this problem bothers you, find ways to contribute to the policies and incentives that systematically reinforce this behavior.  Boycotting it personally will only serve to harm your career and be a drop in the bucket of the larger problem.