- Increasing pollution control costs
- Strong support from parts of the environmental community
- Market-based solutions were designed to reduce pollution
- Separate consideration of goals and policy instruments
- No status quo exists for unregulated pollutants, so there is not constituency to fight for them
- Political shift to accept markets as ways to solve social problems
- Luck put the right people in the right place
Seen in this light, the differences between a command-and-control approach and a market-based approach to dealing with climate change aren't quite so distinct from each other. Granted, if the EPA tries to regulate greenhouse gases using the Clean Air Act, it's going to produce much different results than, say, the Waxman-Markey cap-and-trade plan. But in both cases, the importance of having well-designed rules and a competent civil service enforcing them is manifest. And that, in turn, is not a guaranteed outcome.