"It’s not at all clear how much good the whole apparatus of maximizing behavior in New Keynesian models really does"
" to the extent that such models do seem more or less to work,
it’s only by making some ad hoc behavioral assumptions
that are grafted on to the rest of the structure"
that said
PK still goes "shoo fly"
when Godleynomics buzzes by
"mere hydraulics "
no maximizing agents
too much ad hoc
but PK chooses to knock two of the H-K model's alleged
long run "predictions"
post WWI secular over savings
and
a nearly static Phillips curve
al this
about a decidedly short run model
and aimed at a gent renowned for the accuracy of his " this cycle we're in now " forecasting
again its not hydraulics here
its all history driven
determined by n independent actors
however for that reason
not made to fit any particular actors orders
nor destined to prove providential by any set of explicit social aspirations or "values"
mutual consistency and the justice intrinsic to a higher harmony
has to be imposed by the modeler
so a rough and ready set of historically ad hoc
-- non bottom up agent up derived--
estimated relationships
can work quite as well as these consistent agent inter temporal maximize models
using a limited time horizon like the present cycle
after all stabilization mobilization is all about NOW
yes dynamic adjustments over a series of cycles generates a wild flock of caveats
but none definitively prohibit state macro activism
and only the most wonderlandish render such activism substantively inefficacious