Authorship Practice Guideline

I thought every researcher and student ought to know what the right authorship practice is, but from my observations and conversations with people in MSRA, this does not seem to be the case. Since some of you asked me to write down a guideline, here it is.
To decide if it is worth your time to read this, try to see if you fit any one of these symptoms:
You ever put someone on your paper or patent even though that someone has very little or no technical contribution.
Your name ever appeared on a paper or patent even though you have very little or no technical contribution.
All your published papers so far have more than 2 authors.
If so, you might be hurting yourself. Reasons and remedies are provided below.
The Rules
1. authors contain only people with sufficient technical contributions.
By technical contribution, I mean efforts directly attributed to the paper, including idea, algorithm, coding, demo, experiments, and paper writing. A university professor who merely sent his/her student(s) to work on a project does not qualify for authorship. Anyone (e.g. a manager or a colleague) who does nothing or merely comments on a paper (or patent) draft does not quality for authorship.
2. authors should be ordered according to their relative contributions.
It is not always easy to judge the relative contribution of the collaborators, but my rule of thumb is idea > algorithm/writing > coding/demo > labor (e.g. data collection and experiments). If you have difficulty figuring this out, a good mental exercise is to ask how replaceable that particular author is; the more replaceable, the less value. (This is how supply & demand work in a market economy.)
FAQ
Why is it bad to put a student programmer the first author?
(1) It is not fair, as I stated above. (2) It is harmful to the student's growth. If the student can be a first author by merely coding, what would motivate him/her to go further? (3) It is bad for you (researchers), as in the end you will have a bunch of students or junior employees who know nothing beyond coding, and you will have to do all the other stuff yourself. It is usually not fun.
Why is it bad to put a "guest" professor (i.e. a professor that does nothing to a paper beyond sending students) as an author?
(1) It is not fair, as I stated above. (2) It is harmful to that professor, as he/she would be less motivated to do real research. Plus, putting your name on a paper you know little can be very dangerous to your reputation; remember the American professor who put his name on one of the papers fabricated by the infamous Korean stem cell researcher? (3) We, MSRA, are not doing our job to promote the research capability of China and Asia. Quote from Harry Shum: "it is better to teach someone how to fish rather than giving him free fish".
But that professor will no longer send students if I don't put his/her name on the paper.
I understand this is the Achilles' Heel of MSRA. Ultimately, I don't see this as a major issue as many of you will eventually become (at least) an adjunct professor and will be able to have your own students. In the meanwhile, if you need to bend the rules, go ahead. (I have been and I am still bending the rules myself even at the time of writing this article. We all need to compromise with the reality.) But just keep in mind that this is NOT right and you should strive to fix it eventually.
Why is it bad to put a manager or a colleague (who does not do enough work) as an author?
(1) It is not fair, as I stated above. (2) It can be harmful for the manager's reputation if he/she doesn't know enough about the paper (e.g. a paper containing fabricated results). It can also harm the manager's reputation in another way, as people will know he/she is "rubber-stamping". In the end, people will respect that manager as a powerful political figure, but not an intellectual researcher. (3) It is harmful to you. If you put managers on all your papers, people will not recognize it as your contribution (unless you are already famous to begin with).
On a related note: managers are paid for their "management" work via salary and compensation, not through (your) gratuitous authorship.
But I need other people's help to publish a paper
This implies that your research skill set is not yet complete. Fortunately, most of these skills are learnable. Even for paper writing, you don't have to travel abroad to learn it; I know at least one guy who picked up writing entirely by repeated practice while busting his ass inside Sigma building.
Related Issues
patent invalidation
Abusing authorship for a research paper is never good, but at least it won't be lethal. But doing that for a patent is. I have some recent conversations with several patent lawyers, and my understanding is that patent authors need to be exactly those who have actually made technical contributions (as itemized in the claims); otherwise, the patent can be invalidated in a court. A guy in MSR Redmond even told me that he believed many MSRA patents are subject to invalidation due to the authorship malpractice by managers.
too many authors on a paper
Try to answer this quiz: 10 authors on 10 papers; which option is better for their reputation? (1) 10 authors appear on each one of the 10 papers, (2) each person single-authors one paper. Mathematically they seem to be the same but they have drastically different effects on your reputation. I am not saying that massive collaboration is not good, but research is a very personal endeavor. If you want to get recognition, you will need papers that are associated with you, not your colleagues, manager(s) or institution. Whenever I hear people mention "a paper coming from a bunch of Chinese guys in MSRA", I know it is bad news for *each one* of these guys.
Implementation
Students and junior researchers should start as 2nd or 3rd authors, and they can become a first author only until the day they can finish the paper all alone, with only high level guidance from the adviser. (Sounds harsh? By definition, this is how a Ph.D. thesis requires.)
Senior researchers should start to embark on more personal projects and try not to have everybody collaborate on every project (or worse, gratuitous authorship). I believe the best practice is "one mentor, one student". My experience is that even for projects that have more than 2 people, usually one student and I have done most of the work.
For "guest" professors and managers, it is an art to get things right. A "stop-loss" strategy is to restrict the abuse to a small and fixed number of people that you know well, and cultivate those who are willing to make changes (if needed, feel free to share my article with them). The best strategy, in my opinion, is to become a professor yourself and have your own students.
Finale
In trying to make this article as concise as possible, I might have omitted important information (that I took for granted). Please let me know if you have any questions. I will be happy to give an informal talk if enough of you express interests.
To put my money where my mouth is, let's play a game. For the first MSRA student or assistant/associate researcher who single-authors a SIGGRAPH paper, your travel expense to the conference is on me. (Sorry, only SIGGRAPH can make my eyes blink. Volunteers are needed for other conferences.) The offer is valid throughout my lifetime even after I leave MSRA. Up to the challenge?