Investment decisions and emissions reductions: results from experiments in emissions trading

RESEARCH PAPER NUMBER 942, ISSN 0819-2642, ISBN 0 7340 2598 XEmissions trading is an important regulatory tool in environmental policy making.Unfortunately the effectiveness of these regulations is difficult to measure in the field due to theunavailability of appropriate data. In contrast, experiments in the laboratory can provideguidance to regulators and legislatures about the performance of different market features inemission trading programs. This paper reports on the implementation of three differentinstitutional designs, and presents experimental results investigating important features ofemissions trading regimes: the ability to make investments in emissions abatement, ability tobank allowances and a declining emissions cap, both with and without uncertainty. Thesefeatures are observed in virtually all existing air pollution emissions trading programs currentlyin place and will almost certainly be part of future applications. Like previous experimentalstudies of emissions trading, this paper shows that the efficiency gains expected from economictheory emerge observationally. We also show reduced efficiency when permits are bankable dueto over-banking and when investments in emissions abatement are possible due to overinvesting.These tendencies do not worsen, however, when emissions caps decline