  Perfectly rational decision-makers maximize expected utility, but crucially
ignore the resource costs incurred when determining optimal actions. Here we
employ an axiomatic framework for bounded rational decision-making based on a
thermodynamic interpretation of resource costs as information costs. This leads
to a variational "free utility" principle akin to thermodynamical free energy
that trades off utility and information costs. We show that bounded optimal
control solutions can be derived from this variational principle, which leads
in general to stochastic policies. Furthermore, we show that risk-sensitive and
robust (minimax) control schemes fall out naturally from this framework if the
environment is considered as a bounded rational and perfectly rational
opponent, respectively. When resource costs are ignored, the maximum expected
utility principle is recovered.
