The rest of the article is organized as follows. The next section investigates the costeffectiveness
of alternative emissions control instruments using a relatively narrow, traditional
notion of cost, while the third section considers broader cost dimensions. Section 4
explores other considerations relevant to the choice among emissions control instruments.
Although much of our focus is on policies aimed at reducing emissions, an important
role of decision makers is to consider policies that directly promote the invention or deployment
of new technologies. Therefore, in Section 5 we briefly discuss the rationale for
supplementing emissions control policies with technology-focused policies. Section 6 considers
some further environmental and institutional issues that complicate the choice of
instrument. The final section summarizes our conclusions about instrument choice and identifies some of the challenges faced by environmental economists working in this area
today.