In 1984, he was appointed a member of the Order of the Companions of Honour by Queen Elizabeth II on the advice of Prime Minister Margaret Thatcher for his "services to the study of economics". He was the first recipient of the Hanns Martin Schleyer Prize in 1984. He also received the US Presidential Medal of Freedom in 1991 from President George H. W. Bush. In 2011, his article "The Use of Knowledge in Society" was selected as one of the top 20 articles published in The American Economic Review during its first 100 years.

Hayek became a member of which group in 1984?