Contains fulltext : 178639.pdf (publisher's version ) (Closed access)The article discusses recent attempts in rational choice theory to take account of the opportunity aspect of freedom, i.e., the value of alternatives, in measuring freedom. It is argued that each of these approaches (in terms of fixed preferences, of possible future preferences and of the preferences of reasonable persons) fails to solve important conceptual problems. Furthermore, we argue that differences between measures of opportunity freedom reflect different moral standards for the quality of alternatives, not different conceptions of freedom as such. Hence, we propose to separate discussions about the meaning of the concept of freedom from the issue...