Comment on Chapters 10 and 11

In the economic science there has been a clear development away from an objective economic motive towards subjective motives driving economic behaviour. The emphasis shifted to the economic principle, i.e. goal-directed behaviour. Moreover this principle was also considered to be subjective, because it was acknowledged that efficient behaviour is determined by subjective expectations and subjective information. These developments were not without influence on the cost concepts. ‘Opportunity costs’ are by definition subjective and even the ‘minimum-outlay’-cost concept is acknowledged to be subjective because it is determined by subjective expectations on, for example, future prices and technologies. Moreover expressions such as ‘economic costs’, ‘economic welfare’ became tautological. Recognising the subjective character of costs and benefits there was an intensive compensation debate related to the Pareto principle. Moreover there was a substantial development in the theory of (quasi-)collective goods, in the theory of external effects, in the theory of aggregating individual preferences and in economic index theory.