Land price, government debt, and land-use efficiency in the coastal cities of China under the constraint of land scarcity.

Land scarcity poses a significant challenge for coastal cities in supporting sustainable urban development. This study quantifies the Land Scarcity Index (LSI) for 51 Chinese coastal cities from 2008 to 2018, revealing a phased increase and a transition to high scarcity levels. The findings reveal significant differences in the land price dynamics and fragmentation between commercial-residential and industrial land plots. Under LSI constraints, both commercial-residential and industrial land plots exhibit a trend of decreasing plot areas and increasing prices. We further explore the threshold effects of local government debt (LGD) on urban land-use efficiency, demonstrating that high LGD and LSI exacerbate the price scissors gap, adversely affecting land-use efficiency. Our findings show that, when LGD exceeds 10.43%, increased commercial-residential land prices enhance land-use efficiency, whereas below this threshold, they hinder it. Similarly, the land price scissors (LPS) gap between commercial-residential and industrial land negatively impacts land-use efficiency when LGD exceeds 14.59%. This study provides valuable insights into optimizing land fiscal policies, improving urban land-use efficiency, and addressing the challenge of land scarcity in China's coastal cities.