economy size, 2 questions

[pyrrhos]

I am trying to figure out the size of the bitcoin economy and I have 2 questions for the bitcoin analyzers:

1) Does anybody have any idea how many bitcoins are actually used to buy products and services rather than buying other currencies? Any close approximation of that would provide a good insight of the utility of bitcoin. Perhaps this could help in understanding whether the recent peak is a bubble or not.

2) Has anybody analyzed the bitcoin transaction chain to see what percentage of the existing bitcoins are actually involved in transactions after their creation? Or, in other words, can one see how many bitcoins are actively participating in the bitcoin economy? Perhaps it is possible to see the percentage of not exchanged bitcoins in the last x months or days.

[rezin777]

One is tough (even an approximation). Two has been done, I don't have a link handy, perhaps someone does or maybe a search of the forums would lead to it.

[Stephen Gornick]

Two has been done,

  The metric Bitcoin Days Destroyed is likely along the lines of what you are describing:
  - http://forum.bitcoin.org/index.php?topic=9300.0