Writing someone else's master's thesis: Unethical and illegal?

Think about it this way: Eventually one of those people for whom you write the thesis will be working for your stockbroker and influencing your investments, or working for your doctor or a hospital and influencing your medical care, or working for your government and influencing permits and regulations, or ...

Leaving aside the potential immediate consequences for your "principal" and yourself, you would be making the world a worse place for everyone.

Does that answer your question?

when someone calls me and asks for work-for-hire for his/her thesis; I don't know what to do

Just say NO.

I am struggling to earn money

There are plenty of ways to make money. Why do you want to do this? Writing a thesis is not an easy way to make money.

I think this way of earning money is not good

Okay. Then why do you want to do it?

However there are plenty of websites offering such services

There are plenty of websites offering good jobs, why not pick some other decent jobs?

Now, back to your main question,

Is it legal to write someone else's master's thesis as work-for-hire?

I am not a lawyer. I don't know the answer in your location. In my location, I do know that you will bear serious consequences if you write someone else's master's thesis and get caught . There are cases that people did this and their own degree would be revoked by the Ministry of Education.

As a former academic editor, I agree. You are absolutely right!

Whether or not the act is legal, writing someone else's thesis is helping them commit fraud. You would be helping him or her to obtain a degree that he or she has not earned. The question is, do you wish to participate in that kind of activity? I think you have answered your own question.

Yes, there are (depressingly) many, many, thesis "services" out there. There are many people doing dishonest things in the world. That doesn't make them less dishonest.

It sounds a bit as if someone is pressuring you to do this. If this is true, then for me, dealing with such a person involves finding the wording with which I am comfortable making my stand. Sometimes setting the individual decision in a larger context helps to de-personalize it - I might say that I had considered it, but have decided not to take on full thesis projects as a rule. Or, maybe, I would say that I am going to stick with editing projects for now. Both of these statements relate what my decision is. That is not arguable. I get to say what my decision is. If the person continued to try to argue, I simply repeat what I said, until s/he got it that I was serious. A friend of mine is great at saying, very politely, in many kinds of situations, "I'm sorry, that is not going to work for me," and then offering an alternative. She is voicing a personal preference, against which others can have no legitimate or polite argument. However, every situation is different - each person has to say what reflects his or her thoughts and boundaries.

If this person is desperate because they "have to graduate in May" or whatever, being a former advisor, I would recommend they send see their advisor and confess the truth. Then, try to figure out some options. The world doesn't usually end if students have to finish a course or two over the summer, perhaps you could offer your services for that time. Many students struggle with a large project without supervison. Having a writing coach to keep them on track (you) can help a lot.

If you are an editor struggling for money, that is a familiar problem! More marketing may be necessary, and/or check if your rates are what they should be. If no one ever hesitates when you quote, you may be undercharging. Also, making sure all of your friends know what you are doing, giving them business cards or a flyer, (relatively inexpensive) can help because if you have thirty friends/acquaintances, and they each have thirty, then someone in that 900 must need some editing. This is actually a useful way to search for "regular" jobs too. When I was editing I did find it did take time for marketing to pay off - it seemed like people would file my name away, and when the time came (like six months later) suddenly I would get a bunch of calls.

Hope some of this is helpful; please disregard the rest! And please excuse any typos - I am edited out for today!

Good luck.