Lindblom's Disjointed Incrementalism. Rationality requires complete knowledge and anticipation of the consequences that will follow on each choice. In fact, knowledge of consequences is always fragmentary Since the consequences lie in the future imagination must supply the lack of experienced feeling in attaching value to them. But values can be only imperfectly anticipated.
Rationality requires a choice among all possible alternative behaviors.
In actual behavior, only a very few of all these possible alternatives ever come to mind. The important constraints are informational and computational limits on rationality by human beings. Its procedural rationality depends on the process that generated it. When psychologists use the term 'rational', it is usually procedural rationalty they have in mind. Journ. of Econ.