The evolutionary economic geography approach aims to understand actions of economic actors and paths of change in the context of time and space. It explains how behaviour of agents is situated and conditioned, but not determined, by structures accumulated at the level of organizations and the environment (Boschma (2004) Reg. Studs 38, 9). However, as Martin and Sunley, in a vital summary of the sub-discipline (2007 J. Econ. Geog. 7), point out, just as ‘there is as yet no single, coherent, or widely agreed body of theory or methodology that defines evolutionary economics’, so there is a wide variety of approaches to evolutionary economic geography. Key approaches include using the evolutionary principles of variety, selection, and retention (Essletzbichler and Rigby (2007) J. Econ. Geog. 7). See also Maskell and Malmberg (2007) J. Econ. Geog. 7.