Say you receive an offer for a specific position in a specific department and hope to negotiate a better salary. Aggregated data averaged across all fields, all

Say you receive an offer for a specific position in a specific department and hope to negotiate a better salary. Aggregated data averaged across all fields, all universities and all ranks is not useful. However, the salaries of recent hires, for the same specific position, in the same field at comparable universities will give objective data (and possibly leverage) to negotiate your offer.