Page "Rational choice theory" Paragraph 5

Although models used in rational choice theory are diverse, all assume individuals choose the best action according to unchanging and stable preference functions and constraints facing them.

Most models have additional assumptions.

Those proponents of rational choice models associated with the Chicago school of economics do not claim that a model's assumptions are a full description of reality, only that good models can aid reasoning and provide help in formulating falsifiable hypothesis, whether intuitive or not.

In this view, the only way to judge the success of hypothesis is empirical tests.

To use an example from Milton Friedman, if a theory that says that the behavior of the leaves of a tree is explained by their rationality passes the empirical test, it is seen as successful.