• The empirical literature indicates that, in Phases I and II, the impact of the EU ETS on low-carbon innovation was moderate. The findings of one prominent study, which measures innovation output by patent counts, present a more clearly positive picture. • The empirical literature indicates that, in Phases I and II, low-carbon investments brought about by the EU ETS were typically small-scale, with short amortisation times (e.g., three to five years), producing incremental emission reductions. • In view of the EU’s long-term emission reduction targets, there is scope to improve the dynamic efficiency of the EU ETS by strengthening incentives for low-carbon innovation and investment. Tightening the cap and extending allowance auctioning in a predictable way are the most frequent recommendations in the literature. • There is a compelling economic case, related to innovation spill overs, scale and network economies, competitiveness preservation and energy security, for complementing the EU ETS with stronger R&D policies. • The Innovation Fund – the future EU ETS funding programme for low-carbon innovation – will build on the experiences gained through the existing NER 300 programme in several important respects.