In this response to the case-study of BT, it is explained how privatisation, competition and regulation form part of a complex system of industrial evolution. The paper examines the dynamics of BT culture, and seeks to draw out how privatisation has changed behaviour. It argues that the past fifteen years have been a period of experiment and learning that has greatly changed the culture of residual control. The net impact of these changes has been more favourable than the Milan study perhaps suggests. The importance of counterfactuals in carrying out cost/benefit analysis is underlined and it is emphasised that large scale policy choice must be understood in the context of a comparison of two imperfect institutional systems; no set of institutions is likely to achieve in practice all that can be imagined in theory.