Last but not least, warm thanks go to Jenny Gell for formatting assistance and to the IEA Publications Unit for their support, in particular Cheryl Haines for editing, Robert Youngblood for coordinating, and Angela Gosmann for design. However Page | 5 energy efficiency programmes are often evaluated only on the basis of the energy savings they deliver. As a result, the full value of energy efficiency improvements in both national and global economies may be significantly underestimated.