Loading [MathJax]/jax/output/HTML-CSS/jax.js

Wednesday, June 19, 2013

What role does the information transfer index play?

Other than the solutions to the ODE (see Eqs. 8 and 9 here) for constant information source/destination, there is the solution for "floating" source/destination where: 
Qd=(Qs)1/κ
and
P=1κ(Qs)1/κ1
Let's assume Qs(t)expr0t so that we have
Qdexpr0t/κ
and
Pexpr0t(1/κ1)
I plotted these functions for κ=0.5,1.0and2.0 (Green, blue and red in the picture -- I orignally used a Wiener process with drift in place of the r0t, but then turned down the variance so it would be easier to see).
The dashed lines show P and the solid lines show Qd. The black dashed line (coinciding with the solid blue line) is Qs. We basically get the story that when demand outpaces supply (κ<1), the price level goes up. The opposite happens when κ>1. My next thought, based on the idea that no one knows where economic growth comes from (i.e. total factor productivity), was to ask: what if κ controls the fluctuations of the economy from recessions to growth rates? So I fixed Qs(t)expr0t and let κ be a function of time (this time an autoregressive process; I'm all over the stochastic map):
Here we have the demand (blue solid) outpacing the supply (gray dashed) since κ<1 on average and the price level rising (blue dashed). Here is κ
Now κ=KQsσ/KQdσ where Kσlogσ where σ is the number of symbols used to encode information in the source/destination. This allows us venture a few hypotheses:
  • "Inflation" is when κ<1, i.e. σs<σd, or the number of symbols used in the demand information source is on average greater than the number in the supply information destination. (This mechanism could still be involved.)
  • "Recessions" occur when σd increases and/or σs decreases such that κ falls below its mean.
  • The selection rate of symbols must be lower for higher σ in order for information transfer to remain "ideal" IQd=IQs; a recession in this sense is a slowdown in the selection rate of an increasing number of demand symbols (or an increase in the selection rate of a decreasing number of supply symbols).
  • For small amounts of inflation in a normal economy, this would imply the selection rate for supply symbols is typically slightly faster than the selection rate for demand symbols.
I don't currently know what the deeper meaning is here or if this will lead anywhere. It is interesting, though!

No comments:

Post a Comment

Comments are welcome. Please see the Moderation and comment policy.

Also, try to avoid the use of dollar signs as they interfere with my setup of mathjax. I left it set up that way because I think this is funny for an economics blog. You can use € or £ instead.

Note: Only a member of this blog may post a comment.