Summary: In about 500 words, the entry deals with the concept of choice only from the theoretical perspective of public goods provision, with some references to economic and game theory. The term is never properly defined, the focus being on the object of public choice.
Given that public goods are non-rival and non-excludable, they are underprovided due to free riding.
Thus, since both governments and pressure groups provide collective goods, public choice explores the reasons why they come into existance. Olson's response is the initiative of political entrepreneurs, who can be compared to economic entrepreneurs.
The entry closes remarking that the theoretical advancement in this field depends on a correct conceptualization and modelling of n-persons, dynamic games, while empirical advancement is most likely in the study of environmental lobbies.