Most faculty also teach as well, their paychecks for most part are well earned. The reason the contributions usually drop for mathematicans is less to do with

Most faculty also teach as well, their paychecks for most part are well earned. The reason the contributions usually drop for mathematicans is less to do with losing interest and more that they simple don't have the mental capacity they did in their 20's and 30s into the 50s . Maths is very tough field to do research in.