I am going to apply for PhDs. Since I am applying to a large number of programs, one of my referees gave me two options:
- Reduce the number of programs I apply to (or at least, the number of letters of recommendation that this professor must provide), or
- List the post-doc who mentored me as the referee, and the professor will only co-sign the letter.
In choosing between these options, I am trying to understand: how much will it weaken the recommendation letters if the postdoc is the referee and the professor only co-signs?