In the summer of 1968, Yates received his induction notice. With the encouragement of an academic advisor, he applied for a teaching position at UP's satellite campus in Johnstown, Pennsylvania. He was appointed an assistant professor in 1969. He worked part-time on his degree while teaching. Teaching deepened his radicalism, and he abandoned once and for all the neoclassical economics he had been taught. He also participated in union organizing activities, first with the maintenance and custodial workers on campus and then with the teachers.