Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
A theoretical model of emission reductions is specified that accounts for voluntary and non‐voluntary behaviour regarding the adherence to the Helsinki and Sofia Protocols, which mandated emission reductions for sulphur (S) and nitrogen oxides (NOx), respectively. From this model, we derive an econometric specification for the demand for emission reductions that adjusts for the spatial dispersion of the pollutant. When tested for 25 European nations, the model performs well for sulphur cutbacks. Less satisfying results are obtained for NOx, because the model’s assumption of a unitary actor at the national level is less descriptive. Collective action considerations indicate that sulphur emissions are easier to control than those of NOx.