Economists argue that such market-based policy instruments as environmental taxes and emission trading systems are the best way to target the negative effects of pollution. Yet there is no agreement about whether the use of these instruments is sufficient, whether they are deployed efficiently,...

Economic theory suggests that with a pollution externality and learning spillovers related to renewable energy technologies, the optimal climate policy mix includes an emissions policy and an output subsidy to the learning industry. Instead of output subsidies, feed-in tariffs are often...