During his tenure with Shell, he completed the first part of the economics program at the London School of Economics in 1964 and he also completed a law degree at Leiden University, graduating in 1965.
Selama bekerja di Shell, ia menyelesaikan bagian pertama program ekonomi di Sekolah Ekonomi London pada 1964 dan ia juga menyelesaikan gelar hukum di Universitas Leiden, lulus pada 1965.