The purpose of this study is to evaluate environmental productivity changes in Iranian manufacturing industries, with two-digit ISIC codes, during 2003-2014. For this purpose, Meta-frontier Non-radial Malmquist CO_2 emission Performance Index (MNMCPI) is used. This index considers technological heterogeneities of industries. Empirical results indicate that, during 2003-2014, MNMCPI has grown, on average; the highest growth rate belongs to industries with medium technology. Also, all three indices of EC, BPC and TGC, as MNMCPI components, experienced growth, on average. TGC has the greatest impact in industries with medium technology while BPC has the greatest impact in industries with high and low technology. In general, BPC had the greatest effect on MNMCPI growth.The highest growth rate in EC index is observed in industries with low technology and the highest growth rates in BPC index, which shows the effect of innovation, and in TGC index are observed in industries with medium technology. Therefore, based on TGC index, industries with medium technology level are leading technological industries. Rregression analysis shows that energy intensity has a negative and significant effect and R&D has a positive significant effect on MNMCPI.
