“…For surveys of different measures, see, for example, Isard et al (1960); Bahl, et al (1971); Dixon and Thirwall (1975); Gibbs and Postan (1975); Kruger (2006); Palan (2010). These include the index of regional specialisation (Dixon and Thirlwall, 1975, Krugman;, Shannon's Entropy Index (for example, Aiginger and Davies, 2004;Aiginger and Pfaffermayr, 2004), the Index of Inequality in Production Structure (see Cuadrado--Roura et al, 1999;Haaland et al, 1999;Landesmann, 2000;Percoco et al, 2005), the Theil Index (Brülhart and Traeger, 2005;Ezcurra and Pascual, 2007), and the Hirschman--Herfindahl Index (for example, Sapir, 1996;Davis, 1998;Storper et al, 2002;Aiginger and Pfaffermayr, 2004;Beine and Coulombe, 2007).…”