1. Several books have appeared, simultaneously and independently, trying to identify the underlying processes and interconnections that govern regional innovation (Braczyk, Cooke and Heidenreich 1998; de la Mothe and Pacquet 1999; Ratti, Bramanti and Gordon 1997; DeBresson 1996; Ács 2000). Although these books take different approaches, rely on different methodologies, use different data, and define the unit of analysis differently, they all suggest that there is something fundamental at work at the regional level. While they are all interesting, and illuminate pieces of the regional innovation puzzle, neither singularly, nor in concert, do they answer the bigger question as to why some regions are more innovative than others and therefore grow faster.
2. Jaffe 1989, Ács, Audretsch and Feldman 1991, 1994; Glaeser et al. 1992; Anselin, Varga and Ács 1997, 2000; Varga 1998) and innovation systems (e.g. Saxenian 1994; Braczyk, Cooke and Heidenreich 1998; Fischer and Varga 2000; Oinas and Malecki 1999; Sternberg 1999; Ács 2000).
3. This section draws heavily on Ács and Varga (1999).
4. For such surveys see for example Grossman and Helpman 1991; Helpman 1992; Romer 1994; Barro and Sala-i-Martin 1995; Nijkamp and Poot 1997; Aghion and Howitt 1998.
5. If we are concerned with the regional distribution of A, then regional systems of innovation are the proper unit of analysis.