14-10-2010, 12:31 AM
Comparing the emissions with an alternate run might reveal something: run a tax case where the tax is equal to the observed CO2 marginal. Just replace the spike with a lower value that looks like a reasonable extrapolation of the previous periods.
If the emission constraint is violated, you will have your basic culprit identified.... check who is emitting more than the emission cap case.
If the constraint is not violated, then the spike would be more mechanical than organic. A consequence of how the emissions have been aggregated, who is sitting on which bound etc.