pecialized structure (see Fig. 4). Figure 4 shows how the computer industry consisted earlier of a couple firms which ruled the whole value chain, thus proving end-to-end solutions to customers. A more open architecture enabled vertical disintegration in the computer industry: since the mid-1990 S specialized firms have handled the provision of hardware, computers, operating systems, applications and sales. Bresnahan (1998) notes that vertical specialization of the computer industry lead to vertical competition or co- opetition, where the manufacturers of complementary products compete. Bresnahan and Greenstein (1999) further report that the competition within the computer industry is between platforms and not directly between firms, and that the vertical disintegration of the computer industry has lead to an intensified technological competition as new platforms have been able to challenge older platforms. Usually vertical specialization is seen to lead to a "commoditization" of activ- ities, which again attracts new entrants to the market and intensifies competition. It is often noted to emerge as entry barriers of an industry's segment are reduced (Macher and Mowery 2004). Stiegler (1951, cited by Macher and Mowery 2004), claims vertical specialization to occur in the early phase of an industry's lifecycle as entry firms start to produce those components which have "declining unit costs and substantial minimum efficient scale of production." Re-integration would be common in the mature phase of an industry's lifecycle as vertically specialized firms are no longer supported by the market. It has been shown that often there are development cycles in an industry's structure, where vertical specialization (disin- tegration) and re-integration follow each other. For example, Macher and Mowery (2004) report vertical specialization (or vertical disintegration) in the computers and semiconductors industries, but already find evidence of vertical re-integration in the chemicals industry. Macher and Mowery (2004) also p