I've been at my current university for 3 and a half years. I applied out of undergrad to a PhD program, but my advisor suggested I defend a masters before launching into the PhD just in case. I did last year. Research for the masters took longer than expected so I was done with PhD coursework before even beginning research. To fill the free class time I had my advisor suggested I take business classes (I want to end up in industry) and I eventually convinced him to let me do an MBA during the slow start of PhD research.

Fast forward to this year and I'm doing the MBA full time and PhD work is almost non-existent.

I like the business side of things and for the first time realize I could be happy not doing primary research the rest of my life. I'm currently debating whether staying to finish the PhD is important to me, but I'm not sure whether these feelings are due to my not currently being active in the lab.

If I was providing some value to my advisor I wouldn't feel terrible about letting him fund the rest of my MBA and then leaving. He wouldn't get the amount of work out of me that he would if I stayed for the whole PhD, but he would get something. If I wasn't using grant money I would probably stay until at least summer, get back into the swing of lab and see how I felt, but I am using grant money and I'm not sure thats an ok thing to do.

Do I have an ethical obligation to let my advisor know I might want to leave? Is letting him know going to absolutely shut doors for me?

Does anyone have any advice for ThinkingOfLeaving?

It might be wise just to stick it out till Summer and then see, if as you say, being active in the lab helps you re-engage with the PhD side of things. If, after a bit of time and collecting data or completing lab work or similar and getting some results, you still feel exactly the same way, then it might be a good idea to discuss this with your supervisor and see what your options are.

It is pretty hard to make a considered decision before all the evidence is in-by this I mean, you have given yourself a chance to engage with the actual data. Most of us go through a slow period with the PhD or doctorate where nothing much seems to happen and we want to chuck it all in. But this can pass and we re-engage and carry on. However, sometimes it is a really wise thing to leave a PhD as well. But this is something only you will know-as this is a very personal decision-and until you have given yourself a chance, you probably just don't have enough experience to make that decision as to which you prefer or would be best for you.

If at the end of summer (or whenever a suitable period has passed) you find you do want to leave, you can let your advisor know and would obviously want to discuss this with them. Who knows, you may have completed your MBA or not, you would probably only need to pay for units that you still need to complete. However, you would want to find out if there were retrospective fees applying. EG: You leave the PhD-apply to receive the MBA (which you have completed fee free) but before the University provides accreditation they request fees retrospectively because the MBA is usually a professional qualification that most people have to pay for unless they receive a scholarship or similar. Your funding is for a PhD not the MBA so you might wish to check the rules and regulations and see whether any such concerns are likely to arise.

Another consideration though is whether you are actually allowed to work on the MBA full-time while doing the PhD given that you are funded and whether you have the ability to actually engage with the PhD while completing another degree full time. So you may need to 'pare back' some of the MBA units for a few months so you can actually make a fair judgement. I don't mean cease them, but perhaps complete them at a part time rate, and begin reading and re-immersing yourself in the doctorate just while you give yourself enough time to make a considered decision. Hope this is somewhat helpful.