Theo worked in public administration covering areas of urban renewal (Amsterdam), international university cooperation (Indonesia, Brussels/Central/Eastern Europe); reception of asylum seekers (The Hague); strategy (Ministery of Justice, The Hague). 

He has recently retired and is now a senior adviser to the Van Vollenhoven Institute for Law, Governance and Development (Leiden University), on a part time basis. 

Theo likes to remain active as an ' idea man' or ' innovator ' with respect to crucial issues in the public domain. He (modestly) claims that he is at his best in a role like this when working with others who know more about the issue concerned than then does, for example claiming that being first author of People Flow does not automatically make him a migration expert.