Willem has been the special economic adviser at Citi since 2018. He was the chief economist at Citi from 2010 to 2017. He taught at the LSE and the universities of Princeton, Yale, Cambridge and Bristol. He was an external Monetary Policy Committee member from 1997 to 2000 and the chief economist at the European Bank for Reconstruction and Development from 2000 to 2005. He is married to Professor Anne Sibert.