Road accessibility and land degradation: Evidence from Kenya’s road development between 2002–2022
利用高分辨率面板数据，研究了2002-2022年肯尼亚道路可达性对土地退化的因果影响，发现改善可达性加剧了土地退化，主要通过人口集中和牲畜密度中介，对政策制定者平衡发展与环境保护有参考价值。
Road accessibility improves market access but may intensify pressure on land or enable economic diversification that reduces degradation. We assess the causal relationship between road-driven market accessibility and land degradation in Kenya from 2002 to 2022 using high-resolution panel data. Market accessibility is measured as travel time to the nearest towns based on detailed time-series road network maps, while land degradation is captured using multiple remote-sensing indicators. We find that 81% of Kenya’s land remained stable over the period, while 10% degraded and 9% improved, with forests and croplands degrading the most. Improved accessibility is consistently associated with greater land degradation, primarily mediated by population concentration and, to a lesser extent, livestock density. These findings highlight how infrastructure-driven market integration can intensify land pressures in land-dependent economies, underscoring the need to align road investments with land-use planning to balance development and environmental sustainability.