What Do We Really Assume When We Assume Rationality?

Picture by Josh Abene

In economics, the assumption that economic actors – i.e. people – are “rational” is a common one. By “rational” we mean that people, given a ranking of their preferences, will choose whatever options they prefer the most. Ironically, our definition of “rationality” means doing whatever you feel like.

More importantly, it means that if we propose to know how “rational” economic actors will behave, we are in fact proposing that we are intimately familiar with the emotional life of every economic actor relevant to our model.

It is of course easy to assume a preference ranking when working in the abstract. Also, we can argue that by putting a price or “pseudo-price” on anything and everything, we can just assume that everyone just wants a ton of money because this can be traded in for whatever else you might want. If you ask me, such a argument only proves right those who claim economists are amongst those who “know the price of everything, but the value of nothing.”