Yes, yes, the "marginal revolution" was a huge advance in economics, but when Matt Yglesias referred to total factor productivity as phlogiston economics, I think he missed the real target: utility. I'm going to promote some side comments and random points in a couple of previous posts (here and here) to a post of their own.
If supply and demand is an information transfer process that is related to thermodynamics, then the idea of utility is, well ... silly.
- The pressure of an ideal gas does not fall because an atom feels the diminishing marginal utility of extra volume. The states of the ideal gas at lower pressure become more likely when the volume is increased. The atoms just blunder into it.
- The invisible hand of the market is an entropic force. But that entropic force is not encouraging self-regulating behavior of the ideal gas, and it is not channeling atoms' self-interest.
- If you release a gas into a larger volume (at constant temperature), there will be some fluctuations  in the pressure before it settles down to its lower value. However, that doesn't mean there is a "short run" and a "long run" isothermal expansion curve (isotherm).
- Atoms in an ideal gas don't really have a well defined pressure and volume on their own. Pressure and volume are properties of an ensemble of atoms. Overall, the properties we associate with economic agents are actually only properties of the ensemble system: prices, demand, supply, diminishing marginal utility ... or just utility in general.
- While some atoms may have a large fraction of the thermal energy of the system, it is largely a function of random chance which atom has which allocation. It doesn't mean high energy atoms are "temperature creators" and the situation would be exactly the same if we re-labeled which atom had which energy allocation. On the other side of the equation, it is hard to alter the velocity distribution from a Maxwell distribution given the macroscopic thermodynamic variables if we leave it up to thermodynamic processes.
 The interim state is governed by non-equilibrium thermodynamics and the fluctuation theorem but the information transfer model remains valid under non-equilibrium conditions.