Assessing the threshold effects of road infrastructure construction on farmland use transition: an empirical study in China.

China's rapid road infrastructure construction (RIC) occupies farmland and promotes the flow of rural development factors, which causes farmland use transition (FUT). Although prior research on RIC and their impact on FUT has attracted considerable attention, few studies have investigated the threshold effect of RIC on FUT. Threshold effect is the phenomenon that when the level of RIC reaches a certain critical value, the level of FUT changes abruptly. This paper uses China's provincial panel data from 2004 to 2018 to evaluate FUT. We also consider the spatial spillover effect of RIC and construct a panel threshold regression model to assess the impact of RIC on FUT. The results demonstrate that, considering the spatial spillover effect, RIC significantly promotes FUT, and the threshold effect first rises and then falls. Also, the threshold effect of RIC on FUT also has significant regional heterogeneity. There is a significant single threshold effect for RIC in central and western China, with threshold values of 0.90 and 0.84, respectively, while the spatial lag of RIC in eastern China has a single threshold with a value of 1.10. Our research indicates that the Chinese central government should promote the synergistic increase in RIC and sustainable farmland use by improving the accessibility of road infrastructure and basing RIC planning on the actual development needs of the region.