We don't increase comp for degrees. With that being said, I am in the IT industry and certifications related to particular technologies are more important to us and we have rewarded some with higher salaries for achieving specific certifications.
You have to consider if there is something the business is going to gain from the person achieving the degree. You also have to look at the market. If this person is in a position that would make more money for the experience level and degree level they now have, then you want to be competitive so the person does not leave. I am of the opinion that you take this into consideration during performance review time (the degree, what the business will gain from the person obtaining the degree, the performance level of the person, and the rates in the job market) to see what sort of increase is warranted at this time.