Professor Müenkner studied law from 1955 to 1961 before training as co-operative adviser for developing countries from 1962-1963. From 1963 to 1972 Professor Müenkner was a research fellow and lecturer at Marburg University, Institute for Co-operation in Developing Countries (ICDC).

Professor Müenkner studied for a Doctorate in Law in 1970 and from 1972 became Professor for law of business organizations and co-operative theory, Marburg University. From 1992-2000 he was Director of ICDC and specific areas of research were the development of self-help organisations, co-operative legislation and land law. Since 1992 Professor Münkner has been a patron of Plunkett Foundation before becoming a Fellow in September 2009. From 1990-1995 he was a member of reference groups of the ICA on co-operative values and co-operative principles. In 2000, Professor Müenkner retired from active service at Marburg University. Since 2000 he has been a member of the Faculté Europénne des Sciences du Foncier, Strasbourg.

Professor Müenkner is a consultant of ILO, FAO, UNIDO, UNDAD, USAID, GTZ etc. on revision of co-operative development policy and co-operative legislation in Europe, Africa, Asia and South Pacific.

He is also the author of numerous books and articles on development, policy and law of co-operatives as well as on land law, poverty alleviation and alternative forms of economy, e.g. Legal Framework for Enterprises with Social Objectives in Germany, Marburg 2001; How to form a co-operative self-help organisation? Marburg 2005. As editor and contributor: 100 Years Co-operative Credit Societies Act, India 1904 A worldwide applied model of co-operative legislation, Papers presented at a Colloquium in Marburg, 10-12 September 2004, Marburg 2005; full documentation published by ICA Asia Pacific, New Delhi 2005; textbook and self-study book “Our Co-op, idea – mission – achievements”.