Technological innovation efficiency and its impact factors: An investigation of China's listed energy companies

This study empirically examines the technological innovation efficiency (TIE) and its influencing factors using a multiple input–output stochastic frontier analysis model and a fixed-effect model on a sample of China's listed energy companies between 2008 and 2017. The results revealed the following. (1) The number of patents and research and development investments of China's listed energy companies increased rapidly. However, the overall TIE level of these energy companies was far lower than that of the effective state and showed a downward trend. (2) For the enterprise classification samples, the TIE of state-owned and foreign energy enterprises was lower than that of private energy enterprises, and the TIE of new energy enterprises was higher than that of traditional energy enterprises. (3) For the patent classification samples (IPC1, IPC2, and IPC3), only an increase in IPC2 (the number of patents in fixed buildings, mechanical engineering, heating, weapons, and blasting fields) helped increase the TIE of energy enterprises. (4) Government subsidy and financial leverage are positive factors, while financing constraints, market uncertainty and asset size are negative factors for increasing the TIE of energy enterprises.