The evolutionary model provides important insights into the causal mechanisms of policy change. This works particularly through the notion that the introduction and success or failure of new ideas is a key element in instigating these policy change processes.The survival of an idea is also dependent on key temporal and spatial factors. An idea therefore urgently requires a method of propagation in order to reproduce itself. One means of this idea transmission is through the 'enlightenment function', whereby an effective policy network may gradually alter the assumptions and idea 'images' of policy makers over time.
For example, the interrelationships between ideas, established epistemic communities and time emerge as key variables in determining the enlightenment function in implementation arenas. Time emerges as a vital multi-dimensional independent variable, and in one crucial dimension approximates with a state of readiness as outlined in Vickers' appreciative system.The article employs the case study of the limits of the privatisation idea in British trunk roads policy, and concludes that, even in seeking stability, actors tend to generate unpredictable change.
Evolutionary Theory and the 'Enlightenment Function'In recent years, the evolutionary model has emerged as a valuable, if controversial, tool for examining and analysing the dynamics of policy change (