Green innovation is essential for climate change mitigation, but not all innovative projects deliver equal social value. We consider innovator heterogeneity in a model where the policy maker cannot observe innovation quality and directly subsidize the socially most valuable green innovations. We...

Putting a price on carbon is critical for climate change policy. Increasingly, policymakers combine multiple policy tools to achieve this, for example by complementing cap-and-trade schemes with a carbon tax, or with a feed-in tariff. Often, the motivation for doing so is to limit undesirable...