Returning to academia, Knapp became Associate Professor of Public Policy at George Washington University from 1981 to 1982.

During his presidency, Knapp was a founding member of the Georgia Research Alliance and was instrumental in the creation of the HOPE Scholarship.

Upon leaving UGA, Knapp became president of the Aspen Institute in Washington, D.C., and joined Heidrick & Struggles as a partner in their higher education practice.

In 2005, Knapp joined UGA’s Institute of Higher Education as a part-time Distinguished Public Service Fellow and professor of economics in The University of Georgia's Terry College of Business.

Knapp currently serves as a member of the Board of Trustees at Oglethorpe University in Atlanta, Georgia.