Hello and thanks for reading - I had a suspicion that the sunk cost fallacy might be the one to draw the most attention.

If I have understood your reply correctly - you are saying that the PhD student may be placing her reasoning to keep going on other variables such as employment prospects and the desire to achieve academic status etc. My response here is that this scenario you have presented is therefore simply not an example of the sunk cost fallacy.

If there are rational reasons for the continuation of an endeavour, such as future prospects etc then of course, I agree with you, that is not fallacious reasoning. The sunk cost fallacy comes into play when the main motivator for your decision making is a desire to not let past investments go to waste. For example, if the student wasn't enjoying the degree, realised that the academic job down the line is not what she thought it was going to be etc, but still carried on studying simply due to not wanting her 1.5 years of time and money go to waste - this would be the sunk cost fallacy. This is why I made sure to include the definition below in the post:

"The sunk cost fallacy is committed when one makes a choice not based on what is the best thing to do in that given moment, but in a desire to avoid past investments going to waste."

In hindsight maybe it would have beneficial for me to be more explicit with regards to the fact her decision was purely based on this reason.

As for your suggestion of the genetic fallacy - it was definitely on my list and I am thinking of creating a new post with 3 more used fallacies. Unfortunately the nuances of my opinion on the genetic fallacy deserve their own blog post which I will look to release soon along with a favourite of mine which is the naturalistic fallacy.

Thanks for commenting