Walter Isard died late last week. Isard was the founder of regional science, the economic approach to geography. His seminal book, Location and Space-Economy, was a hugely ambitious work with the goal of developing a theory of economics and space that would encompass general equilibrium theory and international trade as special cases. He brought the German contributions of von Thunen and others into the English mainstream, further developed the spatial interpretation of monopolistic competition (following Hoteling) and applied Leontief's input-output model to geography among many other contributions. The New Economic Geography, particularly The Spatial Economy, the key volume by Fujita, Krugman and Venables can be seen as a direct descendant of Isard's research program (Fujita was an Isard student).
Isard was a Quaker and he also applied scientific insights to questions of conflict, establishing the Peace Research Society (now the Peace Science Society) in 1963. His son, Peter Isard, is a distinguished economist with many contributions to international economics.