"This is the first attempt towards a general theoretical treatise of voluntary environmental agreements, based on a dual institutionalist approach that allows for comparisons between environmental taxes and agreements. The author systematically compares the performance of the radically different CO[subscript 2] policy strategies of Austria, Denmark and the Netherlands - non-intervention, earmarked CO[subscript 2] taxes and energy agreements. From this unique cross-national study, it is concluded that CO[subscript 2] taxes are generally more effective than voluntary energy agreements which, if practised in specific institutional settings, will outperform laissez-faire policy alternatives.".