Sir Hans Wolfgang Singer (29 November 1910 – 26 February 2006) was a German-born British development economist best known for the Prebisch-Singer thesis, which states that the terms of trade move against producers of primary products.

[6] 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.

There, he authored the 1949 UN publication on Relative prices of exports and imports of under-developed countries, where he noted that the terms of trade for primary products had been declining for more than half a century, reversing the improving trend before 1870.

[12] This drew criticism from fellow economists Jacob Viner and Gottfried Haberler and led to his fame as co-originator with Raul Prebisch for the Prebisch-Singer thesis.

[citation needed] Fellow economist Sir Alec Cairncross has said of Singer, "There are few of the developing countries that he has not visited and still fewer that he has not advised.

Singer, like Prebisch, was influential on neo-Marxist development theorists such as Paul Baran and Andre Gunder Frank, although these focused on transfers of profits as a mechanism of exploitation rather than the terms of trade.

The second lecture was held in October 2010 in Brighton with Jomo Kwame Sundaram, Assistant Secretary General of the United Nations Economic Commission for Africa (UNECA).

The third memorial lecture was given by Stephen Chan of the School of Oriental and African Studies at University of London in November 2011 at the German Development Institute in Bonn.