Should my advisor be an author when I found the research question and answered it?

Question

My master's advisor proposed to me a research point that was already published. I found another question, modified the methodology, and got new results, and I am planning to publish the work. He didn't help me during my work and was always telling me that he is not convinced of my ideas. When meetings became unproductive, I stopped visiting and continued on my own. Now, regarding the ethical rules of authorship. Should his name be included?

Update 1: I am adding more info:

1. I am self-funded
2. He used to tell me that he is not convinced without giving me reasons why. He simply was not interested and was underestimating me.
3. My field is numerical optimization and I presented the work at a reputable conference in the field.
4. He wants his name on it but, this was after it got accepted by this prestigious conference.

UPDATE: I asked a young faculty who I know personally and can trust. He suggested that I would need to respectfully discuss my contribution and the advisor's involvement in the paper with the advisor and reach an agreement on authorship.

Answer 1

In my field (public policy), authorship is warranted with contribution. Practically, this means being a primary participant in all areas of the research process, from writing and editing the code use to get your statistical results, developing and conceptualizing the paper, and taking a key role in the decision-making process around the direction it'll take. Playing an active role in the writing process, putting in the time necessary to work on the very fine details to the best of your ability to ensure the manuscript is polished and code sound.

Sure, each author will likely be better at some of these things than others, but so long as your advisor has done at a minimum most of these as I've listed above, then their contribution befits authorship. If he did little to none of these, then he decidedly doesn't deserve to have his name on the paper, at best thank him in the notes for feedback. Beyond him, it'll ultimately be the reviewer's jobs to decide if your papers ideas are worthy.

Answer 2

There isn't enough information here to know.

However, I would note that:

always telling me that he is not convinced of my ideas

seems to be something that you interpret as "my advisor is not useful", when actually, this can be very useful advice. To be useful to the rest of the academic community, you must be able to express your ideas in a manner that others understand, and support any assertions you make sufficiently to convince them.

If your advisor isn't convinced of your ideas, they are giving you the advice that you need to make a better case. This is a form of helping, especially if they help to emphasize for you where your arguments are weakest.

Qualifications for authorship vary by field, so again, I cannot tell you for certain whether your advisor should be an author. In a good situation, the person best prepared to advise you on that is your advisor, though I get the impression from your post that you may not trust them. I don't have enough information to say whether that's reasonable or not.