This may be because the private benefits to firms acting alone were insufficient (whereas the recognition of social benefits makes the actions cost-effective), or because of too high a degree of uncertainty. There may also be a role for public involvement in R&D that will lead to applications with both private and social returns, but which may not otherwise be undertaken without public sector involvement. R&D will be especially important for progress in attaining energy efficiency in agriculture w'hen applied to systems involved in the production process, operational activity and capital goods or farm infrastructure engaged in production. Also, a prudent R&D portfolio includes high risk, potentially high payoff projects, along with those involving lower-risk, incremental improvements.