Professor Emeritus Tönu Puu passed away on July 11, 2020, at the age of 83.

Professor Tönu Puu was born in Tallinn, Estonia. Upon the Soviet invasion of Estonia in 1944, he took refuge with his parents and one sister to Sweden. Tönu grew up in Uppsala. From 1956 to 1964, he studied at Uppsala University. He finished his Ph.D. in Economics, with Professor Tord Palander as thesis supervisor. The thesis was awarded the highest mark possible, and Tönu was honoured with a prize named in memory of the economist Erik Lindahl.

Tönu soon became Associate Professor of Economics at Uppsala University. In 1971, he was appointed full Professor of Economics at Umeå University, the first to hold that position. At his retirement in 2001, he became Professor Emeritus at the University’s Centre for Regional Science (CERUM). During his time at Umeå University, both the Department of Economics and CERUM developed into internationally respected research environments.

Tönu’s research spanned over several areas of economics, mathematics and regional science. He served on the editorial board of journals such as Regional Science and Urban Economics, Networks and Spatial Theory, Chaos, Solitons & Fractals, and Discrete Dynamics in Nature and Society. Through his path-breaking work on spatial and dynamic models, often in collaboration with mathematicians in Providence (USA), Munich (Germany), Kiev (Ukraine), Cartagena (Spain) and Urbino (Italy), he became a leading mathematical economist in Sweden. Tönu Puu published about 300 articles and 25 books and worked on new ideas and manuscripts until the end of his life.

Besides his professional life as a professor, Tönu was a many-sided intellectual. He wrote books on art and science, arranged baroque music festivals, built baroque instruments such as viola da gamba and cembalo. His latest project was to build a new virginal (a rectangular harpsichord with the strings stretched parallel to the keyboard,  popular in the 16th and 17th centuries), a project he unfortunately could not finish.

Tönu is mourned and deeply missed by us and by many colleagues and friends worldwide. But most of all by his children Margareta and Magnus.

Åke E. Andersson, Johan Lundberg, Inge-Bert Täljedal, Lars Westin