 PSEA contracts also cover some non-members, known as agency fee payers, which since 2005 have numbered comparatively about 3% of the size of the union's membership.As of 2014 this accounts for 27,809 "retirees" (15% of total), 7,902 "students" (4%), 816 "reserve," and 552 "substitutes/associates" (both <1%), plus 5,662 non-members paying agency fees, compared to 142,406 "active" members.The stated mission of the Pennsylvania State Education Association is "To advocate for quality public education and our members through collective action."