The principal reason for introducing (and extending) daylight saving time (DST) was, and still is, projected energy savings, particularly for electric lighting. This paper presents a literature review concerning the effects of DST on energy use. Simple estimates suggest a reduction in national electricity use of around 0.5%, as a result of residential lighting reduction. Several studies have demonstrated effects of this size based on more complex simulations or on measured data. However, there are just as many studies that suggest no effect, and some studies suggest overall energy penalties, particularly if gasoline consumption is accounted for. There is general consensus that DST does contribute to an evening reduction in peak demand for electricity, though this may be offset by an increase in the morning. Nevertheless, the basic patterns of energy use, and the energy efficiency of buildings and equipment have changed since many of these studies were conducted. Therefore, we recommend that future energy policy decisions regarding changes to DST be preceded by high-quality research based on detailed analysis of prevailing energy use, and behaviours and systems that affect energy use. This would be timely, given the extension to DST underway in North America in 2007.

Biofuels are a regular focus of public policy. The productivity of innovation in biofuel technologies is rarely addressed either in research or policy. Yet as innovation in any field grows complex and costly it can experience reductions in productivity and diminishing returns to investments. We examine here the productivity of investments in the technologies used to produce biofuels, using data from the U.S. Patent and Trademark Office. The results show that the productivity of innovation in biofuel technologies is declining. Continuation of this trend will in time force reductions in research investments in biofuel technologies. We discuss policy approaches to address declining returns to research investments.

Our research note focuses on whether policy changes in the transportation sector contribute to green innovations, measured as patents. We explore federal policies, specifically energy policies such as Energy Policy Act of 1992 or 2005, that provide incentives for the development of environmentally friendly technologies in transportation. Drawing on a combination of qualitative and quantitative data, we construct and test several novel policy measures while controlling for other factors that may influence green transportation innovations. We develop a unique legislative timeline with the use of key-informant interviews, literature searches, and legislative updates reviews. Only one policy variable (executive orders) appears to have a positive effect on the number of patents in green transportation innovation sphere. High capital expenditures for pollution abatement decrease innovation activity, while high operating expenditures increase innovation activity. The federal policies over the time period analyzed seem to create uncertainty rather than provide a clear incentive for innovation. The executive orders may affect innovation levels; further tests are needed with the changes in political leadership. The results of our research note signal that stronger and more consistent incentives at federal level may be necessary to realize desired policy outcomes.