Sir Hans Wolfgang Singer (1910–2006) was a German-born British development economist best known for the Singer–Prebisch thesis, which states that the terms of trade move against producers of primary products. He is one of the primary figures of heterodox economics. Early life He was born in Elberfeld, Germany (then the German Empire) on 29 November 1910. A German Jew, Singer had intended to become a medical doctor before he was inspired to study economics after attending a series of lectures by prominent economists Joseph Schumpeter and Arthur Spiethoff in Bonn. Singer fled the rise of Adolf Hitler in 1933, arriving in the United Kingdom as a refugee. Career In 1933, Schumpeter convinced John Maynard Keynes of Cambridge University to accept Singer as one of his first PhD candidates, and Singer received his doctorate in 1936. His first academic post was in Manchester where he stayed from 1938 until 1944. Under Keynes, he produced two papers in 1937 and 1940 studying unemployment. Keynes had also helped secure Singer's speedy release after his former student was interned by the British government at the start of the Second World War. In 1938, Singer applied for British citizenship, listing as references Keynes, William Beveridge, William Temple, and the vice-chancellor of Manchester University. His request was granted in 1946. In 1947, he was one of the first three economists to join the new Economics Department of the United Nations (UN), in which he remained for the next two decades. During his time at the United Nations, Singer was the Director of the Economic Division of the United Nations Industrial Development Organization (UNIDO), Director of the United Nations Research Institute for Social Development (UNRISD), and was closely involved in the creation of the Bretton Woods framework and the post–World War II international financial institutions. He published a 1950 empirical study examining the costs of international trade, drawing criticism from fellow economists Jacob Viner and Gottfried Haberler. This led to his famous co-credit with Raul Prebisch for the Singer–Prebisch thesis. However, the two economists had not collaborated but had come to similar conclusions separately. Singer's supporters are quick to point out that it appears that Singer wrote down the thesis before the more well-known Prebisch. The fundamental claim of the hypothesis is that in a world system in which poorer nations specialise in primary products such as raw minerals and agricultural products that are then shipped to