Some things to note:
- The EU ETS is mostly a pre-allocated system, i.e., permits are not auctioned, with allocation determined by "grandfathering".
- It covers only power and industrial emissions.
- The price evolution of the 2007 and 2008 permits are wildly different, with the 2007 permit prices collapsing and the 2008 prices maintaining a trading range.
- MIT concludes that the economic impact has been minimal.
- I notice that the report doesn't really cover whether carbon emissions were actually reduced.