Summary Using a duopoly model of a patent race, it is shown that a stricter environmental policy might increase the probability of a sleeping patent instead of encouraging environmental technological progress. Two scenarios are discussed. The first concerns the regulation of a firm that competes...

"Tradable permit regulations have recently been implemented for climate change policy in many countries. One of the first mandatory markets was the EU Emission Trading System, whose first phase ran from 2005-07. Unlike taxes, permits expose firms to volatility in regulatory costs, but are...