On Wed, 8 May 2019, Alecos Papadopoulos wrote:
A clarification please Allin: are you referring to the
"Ramsey" or to the
"Solow" growth model? I am confused because in the Ramsey model, we are not
heading towards the Golden Rule steady state. On the other hand you do
mention the Euler equation...
I'm referring to the Ramsey model, which IMO ought to be general
enough to include the case of a zero discount rate (so that the
steady state is the same as under the Golden Rule).
In the Solow context, the usual idea of how to get to the
maximum-consumption steady state is simply to set the saving (and
investment) rate equal to its steady state value: then you're bound
to get there, regardless of your starting point. But the Ramsey
approach suggests that may not be optimal.
Suppose we're approaching SS from below. Perhaps we should save at
above the SS rate at first, to get to SS faster? Or the opposite:
gradually increase the saving rate to its SS value? Even with a zero
discount rate this sort of choice is going to depend on the rate of
diminishing returns to consumption (e.g. the parameter in a CRRA
utility function, which I'll call sigma.).
Dynare is able to show me that the Euler-obeying perfect foresight
path can start with saving above or below the steady-state rate
depending on the value of sigma. And I can confirm this increases
total utility over the transition to SS, relative to the constant
saving-rate case, by having gretl compute utility for the latter.
Also what do you mean by "advantage"? In intertemporal
utility terms or
something else?
Intertemporal utility.
Allin