Hmmm. Didn't Boltzmann put S = k \log \Omega on his grave? I think we are taking different lessons from stat mech. To me, the triumph of stat mech is that macroscopic phenomena (like entropy S) can be explained in terms of microscopic quantities (like Omega).
At least with S, even before stat mech there was a precise process to measure S from a P/T phase diagram. And there was a procedure to reproduce a phase diagram for an arbitrary compound.
Yet have you ever seen someone calculate the values of C, I, G, and Y from raw data? Like, a reproducible research document which calculates these from a public database of individual transactions, perhaps from a virtual economy? Everyone starts from government statistics to justify the government's activities.
You can directly measure the macroscopic quantity of inflation on a microscopic basis by simply tracking prices over time. But the other quantities that a lot of macro reasoning seems to be based on do not have simple measurements. That is the fundamental reason for deep skepticism about macro. Where's the raw data and the source?
Because we are making decisions about trillions of dollars by verbal argument rather than open public datasets and source code. Given a database with an anonymized, representative sample of tax returns, credit card transactions, bank account deposites, new company incorporations and the like (many of which would be a matter of public record) you could probably go pretty far with some basic scatterplots. Yet this is not the culture in economics.
No, we aren't taking differeent lessons from stat. mech. - your understanding of thermodyanmics is flawed (there are no two views here - this is physics).
S = k ln W is an entropy model for an ideal gas with uncorrelated particle motions and inelastic collisions. It doesn't explain the "entropy" of a real system.
There is no precise way to measure S for any real fluid whatsoever. S, at a microscopic level, isn't even well defined (disorder? - but that's just an interpretation for S, not a definiton). Phase diagrams only allow you to measure changes in S - and that's only because (assuming reversibility), delta(S) can be explained with change in pressure and temperatures (both are aggregate variables). And when a process is irreversible (which most real-world processes are),the only thing you can say is that the change in S would be greater than what you can compute using T, P, heat transferred and work done.
Raw data to calculate C, I, G and Y are freely available for public use at : http://www.nber.org/data/ . The accounting framework on which the above measurements are based is described here: http://unstats.un.org/unsd/nationalaccount/docs/SNA2008.pdf
(individual nations implement their accounting frameworks, as the NBER does for the US, according to the guidelines above).
At least with S, even before stat mech there was a precise process to measure S from a P/T phase diagram. And there was a procedure to reproduce a phase diagram for an arbitrary compound.
Yet have you ever seen someone calculate the values of C, I, G, and Y from raw data? Like, a reproducible research document which calculates these from a public database of individual transactions, perhaps from a virtual economy? Everyone starts from government statistics to justify the government's activities.
You can directly measure the macroscopic quantity of inflation on a microscopic basis by simply tracking prices over time. But the other quantities that a lot of macro reasoning seems to be based on do not have simple measurements. That is the fundamental reason for deep skepticism about macro. Where's the raw data and the source?
Because we are making decisions about trillions of dollars by verbal argument rather than open public datasets and source code. Given a database with an anonymized, representative sample of tax returns, credit card transactions, bank account deposites, new company incorporations and the like (many of which would be a matter of public record) you could probably go pretty far with some basic scatterplots. Yet this is not the culture in economics.