The assumption of homo economicus, or even the lesser assumption of perfect rationality, cannot possibly be true. If even the assumption of perfect rationality were true, all economists would have the same opinions.
The only possible exception would be that economists of perfect rationality could have different opinions if their opinions were based on different information. We would have to say then, the assumption of perfect rationality, but bounded information.
However, let us suppose a situation with bounded information and perfect rationality, and two economists with differing opinions. Then one or the other or both economists do not have sufficient information to properly analyze the situation.
In general we have: Given a sufficiently competent computer, its output is purely a function of the input. Therefore, given two sufficiently competent computers, if they differ in the output, they differ in the input.
However, in the fact, if the union of opinions in economics is less than the space of all possible (reasonable) opinions, it is uncertain that even one economist is capable of both perfect rationality, and unbounded information.
It should be mentioned that the techniques of rationality are many and varied, and require considerable information input to form and develop.Thus bounded information would seem to at least render unlikely the development of perfect rationality.
Finally, \the mention of information brings to the fore the field of information theory, which seems not to have attracted much attention among economists.
