"Governments support particular firms or sectors by granting low interest financing, reduced regulation, tax relief, price supports, monopoly rights, and a variety of other subsidies. Previous work in partial equilibrium shows that subsidies to environmentally sensitive industries increases...

"This paper develops a simple model of a polluting industry and an innovating firm. The polluting industry is faced with regulation and costly abatement. Regulation may be taxes or marketable permits. The innovating firm invests in R&D and develops technologies which reduce the cost of pollution...