The investment in Major Construction Projects (MCPs) has a counter-cyclical impact on quantitative GDP increases during the recession period. However, its impact on the quality of economic growth is still unknown. Based on the data of prefecture-level cities in China from 2008 to 2017, we construct an economic Quality Growth Index (QGI) including sustainable development factors and take the PPP (Public–Private Partnership projects) policy as a quasi-natural experiment to design a

more »

... ifferences (DID) strategy for the first time to estimate the effects of the MCPs investment on the sustainable development of regional economies. We find that the MCPs investment can significantly improve the quality of regional economic growth. The MCPs investment can improve the quality of regional economic growth by enhancing innovation and entrepreneurship at the regional levels. Our findings may provide empirical evidence to support the policy of increasing investment into infrastructure constructions to promote sustainable development in the current economic recession under the COVID-19 pandemic.