A word for someone who does tasks just to get rid of them [duplicate]

Solution 1:

The expression :

Finished for the sake of finishing, may express the idea you want to convey.

• For the sake of something: (from www.macmillandictionary.com)
  • for the purpose of doing, getting, or achieving something

Solution 2:

In economics, the sunk cost fallacy is used to describe the tendency to keep investing in something because you've already invested in it, because you feel that to stop investing in it would make your previous investments a waste. This is usually used in terms of money (for example, a manager buys a computer system that doesn't work well, but keeps using it because he thinks that if he doesn't use it, the money he paid for it will be wasted), but it can also be referred to in terms of time, as in your example: You've already spent time reading 45% of the book, so you might feel that to stop reading it now would make the time you already spent reading it a waste. Of course, this is a fallacy because the manager has spent his money whether he keeps using the computer system or not, and you have already spent your time whether you finish reading the book or not.

Solution 3:

A slog?

to keep doing something even though it is difficult or boring

http://www.merriam-webster.com/dictionary/slog

Solution 4:

You could say that you feel obligated to finish the book.

This could be due to a desire not to waste the money spent on the book, or to avoid disrespecting the author, or any number of things. If you wanted to reach the end just to see what happens, you would be looking for closure.

e.g.

Because the book was so expensive, I felt obligated to complete it.

Because I wanted closure, I felt obligated to complete it.