In 2004 back in Amsterdam he was appointed Professor of Economics at the University of Amsterdam, and Director of SEO Economic Research from 2004 to 2006. From 2006 to May 2013 he was Director of the Netherlands Bureau for Economic Policy Analysis. From 1 October 2013 he was appointed as the Montague Burton Professor of Industrial Relations and Labour Economics at Cambridge University.[2][3] From 2018 onward, he is distinguished professor at Utrecht University.[4]