When it was launched in 2005, the European Union emissions trading system (EU ETS) was projected to have prices of around €30/ton CO2 and to be a cornerstone of the EU's climate policy. The reality was a cascade of falling prices, a ballooning privately held emissions bank, and a decade of low...

Policy makers in the EU and elsewhere are concerned that unilateral carbon pricing induces carbon leakage through relocation of emission-intensive and trade-exposed industries to other regions. A common measure to mitigate such leakage is to combine an emission trading system (ETS) with...