Carbon productivity growth in China's thermal power industry: Empirical evidence using a bootstrapped Malmquist-Luenberger productivity index approach with fixed-sum undesirable outputs

The total amount of carbon emissions is limited by a fixed-sum constraint in the context of China's dual carbon target, a factor ignored in previous studies on carbon productivity. To address this gap, this study proposes a bootstrapped Malmquist-Luenberger productivity index approach with fixed-sum undesirable outputs. The proposed method not only considers the fixed-sum feature of undesirable outputs; it also reduces the calculation error caused by small samples and improves the accuracy of the measurement. We then apply the proposed approach to measure the carbon productivity growth of the thermal power industry in 30 provincial regions in China from 2011 to 2020 and analyze the driving forces of carbon productivity growth. The empirical results show that during the study period, China's overall carbon productivity increased with an annual average growth rate of 0.61 % due to CO2 emission efficiency improvement and technological progress. Additionally, 18 provincial thermal power industries had average carbon productivity growth rates between 0.06 % and 4.86 %, while the remaining 12 provinces showed carbon productivity declines at rates ranging from 0.03 % to 2.90 %. The driving forces of such growth differ among the 30 provinces. Policy suggestions are given for improving the carbon productivity of China's thermal power industry.