He was the President of the Thailand Development Research Institute and later served as Minister of Finance in Surayud Chulanont's military junta.
Prior to joining the cabinet, Chalongphob had no experience in government and was an economist.
Sussangkarn received BA and PhD degrees from the University of Cambridge.
After graduation, he taught at the Department of Economics at the University of California, Berkeley during 1977–79.
Sussangkarn died in Bangkok[citation needed] on 23 August 2024, at the age of 74.