Recent years have seen continuing debate about the factors underlying the process of economic development, but increasing consensus that technology and innovation play a key role. Increasing energy supplies are seen by some observers as fundamentally necessary for economic development, while others believe that a process of dematerialisation is underway in a shift to a "knowledge-based" economy. Energy futures will depend heavily on the process of technology innovation and transfer, which is affected by investment in research and development (R&D) and education, management styles and culture, market and regulatory incentives, perceived human needs, and many other factors. The primary energy carbon dioxide (CO2) emission intensity of the world economy has fallen by only about 1.1% per year in the last 20 years. However, circumstances are imaginable where energy intensity could decline by 2-3% per year in the long term. It is also possible that energy intensity could increase.