本文在效率工資談判的架構下，建立一個利益團體模型，用以比較對污染減量預補貼以及對污染課稅之效果。在廠商數目不變的情況下，若政策制定不受利益團體的時，補貼與課稅會導致相同的污染排放與社會福利水準。然而一旦考慮利益團體的影響，將環境政策內生化後，補貼與課稅將對廠商獲利有不同的影響，此將改變利益團體的遊說行為。在利益團體的遊說率均不為零的情況下 ，在補貼政策下，由於利益團體將追求更高的補貼率，因此政治均衡的環境管制將效使社會福利最大的管制更為嚴格；而在課徵污染稅制度下，利益團體將追求較低的稅率，致使均衡環境管制較適管制較最適管制來得寬鬆。本文進一步指出，政治均衡下的環境政策與廠商跟工會在勞動市場中的議價能力有關，在某些情況下，即使利益團體的影響力存在，均衡管制仍將等於最適管制結果。雖然補結有較佳的污染防治效果，但此並不意著補貼必然較課稅更有效率，須視補貼制度下的污染基準值與實際污染排放量的大小而定。當基準值愈大，課稅愈有可能較補貼產生更高的社會福利水準。

In a framework of efficient wage bargaining, we construct an interest-group model to compare the pollution control and welfare effects of abatement subsidies with that of emission taxes. When the number of the firms is fixed and there is no presence of interest groups, abatement subsidies and emission taxes are shown to be equivalent. However, once the influence of interest groups has been taken into consideration, the two instruments are no longer equivalent. The abatement subsidies and the emission taxes give rise to different impacts on the profitability of the firm, leading to different lobbying behaviors of interest groups. Furthermore, we show that the subsidy regime will generate less pollution emissions than the charge regime. The reason for this is that the interest groups will intend to increase the subsidy rate, whereas they will intend to depress the emission tax rate. Although the subsidy regime has a better pollution control effect, abatement subsidies are not necessarily welfare superior to emission taxes. The base under the subsidies is crucial in determining the welfare effects of the two instruments; the larger the base level, the more likely it is that charging a pollution tax will give rise to a higher level of social welfare.