De Percy's PhD thesis, supervised by John Wanna, developed a model of path-dependent, punctuated equilibrium[4] to facilitate process tracing in a comparison of communications technology policy outcomes in Canada and Australia.

[5] De Percy has co-edited scholarly works on transportation policy,[6] public administration,[7] and the impact of the COVID-19 pandemic on foreign aid and international relations.

He is the Chairman of the ACT and Southern NSW Chapter of CILTA,[19] and served as the Vice President of the Telecommunications Association (TelSoc) from 2022 to 2024.

[21] De Percy collaborated with the Australian Civil-Military Centre on a project on Syrian refugee women in Jordan and Lebanon, where he co-authored three commissioned occasional papers.

[22] De Percy teaches political science subjects, and has edited and written several books and scholarly articles on the topic.