Policy shock effect of SDP on environmental total factors productivity: 53 coal cities versus 165 non-resource-based cities.

The trend of economic decline for coal cities is a serious threat to the high-quality development of China's economy, and how to improve the environmental total factor productivity (ETFP) has become an urgent issue. Based on the framework of data envelopment analysis (DEA), this paper estimates ETFP using the global Malmquist-Luenberger productivity index (GMLPI). We decompose GMLPI into environmental technical efficiency change (ETEC) and the best practice gap change (BPGC). Then, the difference-in-difference (DID) model combining propensity score matching (PSM) method is used to investigate the effect of the Sustainable Development Plan of National Resource-based Cities (2013-2020) (SDP) aiming to improve ETFP. The results indicate that (1) On average, the GMLPI and BPGC are rising, while the ETEC is decreasing in the observed sample period; the western regions have the biggest BPGC, while the eastern regions have the biggest ETEC; (2) The SDP significantly improves the GMLPI and BPGC but has little effect on the ETEC; Coal cities located in eastern and central regions have policy effect, while the western regions do not have. (3) The SDP affects ETFP through slowing down the economic growth rate and reducing population agglomeration, but promoting the optimization of industrial structure. Those findings have policy implications for improving ETFP and promoting the industrial upgrade of coal cities.