In 2000, he wrote an essay Het multiculturele drama[2] (approximate translation: "The multicultural drama”) which was very influential in shaping the debate on multiculturalism and immigration in the Netherlands.
His 2007 book, Het land van aankomst, was published in English in 2011 as "Immigrant Nations", and deals with the overlaps between multiculturalism in the Netherlands and immigration to the Netherlands.[3] The central idea of this book is that "immigration always has been and is a process of alienation for both the newcomers and the natives".