A Malmquist CO2 emission performance index based on a metafrontier approach

Considering carbon dioxide (CO2) emitters in different groups that may not have the same technology, this paper extends the Malmquist emission performance index (MCPI) for measuring changes in CO2 emission performance using a nonparametric metafrontier. The MCPI can be decomposed into two components: efficiency change index and technological change index. Meanwhile, the interrelationships between two MCPIs, relative to the metafrontier and the group frontier respectively, are also examined by the key factor, technology gap ratio (TGR).