Michel Trommetter

Variety and niche creation in aircraft, helicopters, motorcycles and microcomputers

Evolutionary theories of economic development stress the role of variety as both a determinant and a result of growth. Our empirical understanding of the role of variety, however, is still limited. We propose two variety measures, one based on entropy and one based on Weitzmans maximum likelihood procedure. It is argued that the two measures are complementary since they highlight different aspects of variety. Entropy is based on frequencies and indicates the statistical variety, while Weitzmans measure is based on the distance between products, and indicates the degree and structure of differentiation of a population. We apply the measures to product characteristics of four technologies (aircraft, helicopters, motorcycles, and microcomputers). The results on the three transport technologies show classic evolutionary specialisation patterns that can be understood on the basis of niche theory. In these cases, the changes in variety are related to changes the scope of services a technology can deliver analogous to the size of a habitat of a biological species. The results on microcomputers call for another explanation, since we found that variety decreased while the scope of services increased rapidly. In this case, the rapid fall in costs per unit service decreased so rapidly that the lower end of the market continuously disappears when the higher end of the market is extended. The results on microcomputers call for extending niche theory including the rate of change in costs.

Variety and economic development : conceptual issues and measurement problems

For any evolutionary theory of economic development, the understanding of the determinants of variety and its effects on economic systems is of central importance. On the one hand, increasing returns tend to standardize technologies thus reducing product variety. On the other hand, the resulting efficiency gains generate resources that allow for the development of new products that contribute to long-term growth. The net variety effect on economic systems remains an empirical question. We propose two variety measures, the entropy measure and Weitzman’s maximum likelihood procedure. It is argued that the two measures are complementary since entropy indicates the variety in a frequency distribution, while Weitzman’s measure is based on a distance measure. We apply both measures to data on product characteristics of aircraft (1913–1984) and helicopters (1940–1983). Aircraft variety has been increasing rapidly after the emergence of a dominant design in the thirties. The rising variety of aircraft is related to the increase of the span of performance, which is analogous to the size of the habitat of a biological species. The larger the habitat, the larger the number of niches which is expected to occur. A dominant design is established in each niche. Helicopter variety has been decreasing after a dominant design emerged as innovations hardly in-creased the span of performance. The presence of aircraft technology in the higher end of the helicopter market limited the commercial potential of technological improvements in helicopters.

Players, property rights and research in the plant sector: a historical perspective

Before we can speak about the different options for the future of management and the definition of property rights for living organisms in terms of property rights, access and benefit-sharing linked to genetic resources, it is necessary to analyse past developments. This gives us a better understanding and thus allows us to anticipate for the future, the links that could exist between the evolution of intellectual property rights for living organisms and the evolution of the organisation of the conservation and breeding of plant varieties.