How do reasons accrue?

Reasons can interact in a variety of ways to determine what we ought to do. For example, I might face a choice of whether to work on this paper or socialize with friends. And it might be that the only relevant reason to work on this paper is that I have a deadline coming up soon and that the only relevant reason to socialize is that it is relaxing. In this case, whether I ought to work on the paper or ought to stay at home is determined by which of these reasons is stronger