Finalists: Melbourne, Sydney A, Sydney B
Glasgow played host to the Worlds for the second time in 1990. Yale University (Matt Wolf & John Wertheim) took home the first American victory in the history of the tournament, over a field of about 165 teams. Hong Kong was represented, and the American Academy in Athens, Greece returned. A Polish team was there, too.
The previous summer, a group of 10 people had toured Eastern Europe to teach debating. One of the Soviet teams the group had met on the tour came to the Worlds that year. Princess Anne was the honored guest at a reception for the Debating Union Presidents before the final round. She presented the award to the winning team from Yale, who were the victors in the finals against three Australian teams.
This History of the World Debating Championships comes in 3 parts. From 1976 to 1990 it is taken almost word for word from the 1991 Toronto WUDC Tournament booklet. Who wrote it isn't known but it was provided by Randal Horobik. At the start of the section on Worlds in 1981 is an extract from an e-mail by Clark McGinn, Convenor of Debates, GU Union 1980 -81 and 1981 and Convenor of the First World Debating Competition, 1981. The history since 1991 has been compiled initially by Colm Flynn and edited by many contributors to Wikipedia. Unfortunately Wikipedia deleted the history due to copyright concerns so we are back here. Hopefully anyone who contributed to the Wiki article before it was deleted will be happy to see their work preserved here.