This paper explores different measures of energy efficiency performance (“MEEP”) and
considers the importance of so-called boundary definitions when measuring energy performance,
and how these affect the appropriateness of country comparisons to guide policy decisions.
The paper also addresses the limitations of both energy intensity and technology diffusion
indicators as measures of energy efficiency performance. A case study on Japan’s iron
and steel industry illustrates the critical role of proper boundary definitions for
a meaningful assessment of energy efficiency in industry.