  Arthur's (1988) model for competing technologies is discussed from the
perspective of evolution theory. Using Arthur's own model for the simulation,
we show that 'lock-ins' can be suppressed by adding reflexivity or uncertainty
on the side of consumers. Competing technologies then tend to remain in
competition. From an evolutionary perspective, lock-ins and prevailing
equilibrium can be considered as different trajectories of the techno-economic
systems under study. Our simulation results suggest that technological
developments which affect the natural preferences of consumers do not induce
changes in trajectory, while changes in network parameters of a technology
sometimes induce ordered substitution processes. These substitution processes
have been shown empirically (e.g., Fisher & Prey, 1971), but hitherto they have
been insufficiently understood from the perspective of evolutionary modelling.
Implications for technology policies are discussed.
