Perfect rationality presumes cost-free computation and closed problem sets

Evidence

A serious consideration of these factors would necessarily force the abandonment of the cleaner and simpler assumption of perfect rationality, but this is an assumption which is plainly wrong and, if pushed, is less clear than it might at first seem. On the one hand it requires the additional assumption that computation is cost-free, and thus leads to a selective treatment of the costs involved in any economic decision. On the other it must also assume that decisions are made in a world where all problems have a close set of solutions — because, if it does not, then unending computation becomes possible. Unfortunately for this assumption, it would appear that many real-world problems are distinctly open ended. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 728

Categorization

• DEFINE: Spells out the two hidden premises of the perfect-rationality assumption: zero computation cost and closed solution sets.