The vast urban–rural income gap (URIG) is a global challenge, particularly severe in underdeveloped regions. While the income-generating effects of transportation improvements are widely accepted, their income distribution effects remain controversial. This study focuses on national poverty-alleviated counties in central and western China, using a mixed-methods approach to quantitatively test the non-linear relationship between highway improvements and the URIG and qualitatively analyze the reasons behind the threshold effects of regional economic development levels. The main findings are as follows: first, regional economic development levels exhibit a double-threshold effect, with the impact of highway improvements shifting from widening to narrowing the URIG after surpassing the second thresholds. Second, inter-regional highways have a limited impact on narrowing the URIG, while intra-regional highways significantly reduce the URIG once crossing their thresholds, reflecting the distinct functions of different highway classes. Third, the heterogeneity analysis reveals that the impact of highway improvements on the URIG varies depending on the external environment surrounding residents, including both the indirect and direct environments. Fourth, from the perspective of rural labor transfer to non-farm employment, regional economic development levels create threshold effects in two ways: for local employment, they influence non-agricultural industry growth and job distribution following highway improvements, affecting rural laborers’ participation; for migrant employment, they impact human capital investment, influencing rural laborers’ skills and wage returns after highway improvements.

This study aims to systematically evaluate the dynamic effects of rural–urban migration experiences during compulsory education on human capital accumulation in China from a life-course perspective, with a focus on both the short-term and long-term outcomes for migrant children and the spillover effects on left-behind children. From a life-course perspective, this study examines the nonlinear temporal effects of rural–urban migration experiences during compulsory education on the human capital accumulation of migrant children in China. Using a cohort of rural children recorded in the 2012 wave of the China Family Panel Studies (CFPS) and their follow-up information in the 2020 wave, an endogenous switching model is constructed for empirical analysis. The results show that: (1) Rural–urban migration during compulsory schooling has a negative short-term impact on the human capital accumulation of migrant children, while its long-term effects remain positive. (2) Social integration difficulties, reflected in declines in self-efficacy and social trust, constitute the negative mechanism, although this influence weakens as migration duration increases. In contrast, improvements in public education quality, enhanced family educational processes such as increased parental time investment, and gains in non-cognitive abilities including higher self-educational expectations and better mental health serve as the positive mechanisms. (3) Rural migrant children cause negative spillover effects concerning the human capital accumulation of left-behind children because the outflow of students reduces the educational accessibility of left-behind children through distance effects and lowers the quality of rural primary and secondary schools through scale effects.

The impact of rural-urban student mobility on the efficiency of resource allocation in China’s rural households is crucial for refining policies related to rural migrant settlement and the balanced allocation of urban and rural educational resources. Drawing on theoretical insights, this study employs a mixed methods approach—primarily qualitative, with quantitative support—to empirically test the impact of rural-urban student mobility on the resource allocation efficiency of rural households in China. Utilizing micro-survey data from China Family Panel Studies (CFPS), this study applies ordinary least squares (OLS) models, propensity score matching difference-in-differences (PSM-DID) models, and endogenous switching regression (ESR) models to ascertain the direction of this impact. Furthermore, this study incorporates in-depth interview data gathered from field research in D County to explore the dynamic mechanisms of resource allocation adjustments within these households. The results show that rural-urban student mobility significantly reduces the efficiency of labor resource allocation and agricultural production in China’s rural households. The impact is heterogeneous across different groups, most negatively affecting households with limited labor resources, lower educational levels, lower incomes, more productive fixed assets, and less self-owned land. Mobility leads to suboptimal occupational choices, resulting in decreased labor resource efficiency. Additionally, it distorts agricultural production by leading to labor loss, reduced investments in agricultural productivity, and misaligned land allocation decisions.

The sustainability of rice-cropping systems hinges on balancing resources, output, and environmental impacts. China is revitalizing the ancient ratoon rice (RR) system for input savings and environmental benefits. Prior research has explored the RR system’s performance using various individual indicators, but few studies have focused on its overall balance of these factors. Environmental efficiency (EE) analysis addresses this gap. Using field survey data from Hunan Province in China and the slacks-based data envelopment analysis method, we quantified the EE of the RR, double-season rice (DR), and single-season rice (SR) systems. Key findings include: (1) the RR system outperforms in carbon emissions and non-point source pollution; (2) the RR system’s EE is 0.67, significantly higher than the DR (0.58) and SR (0.57) systems, indicating superior performance; and (3) despite its relatively high EE, the RR system can still improve, mainly due to input redundancy and production value shortfall. These findings provide strategies for optimizing RR systems to enhance agricultural sustainability.

Rural–urban student migration during the compulsory education stage is a transitional phenomenon in China’s socio-economic development and a crucial issue for achieving the goal of urban–rural integration. This paper, grounded in theoretical analysis, constructs a “willingness-capacity-behavior” framework. Based on field survey data from 916 rural households and in-depth interview materials from County D, Province X, China, this study employs a bivariate Probit model and qualitative analysis methods to explore the driving factors and formation mechanisms of rural households’ rural–urban student migration decisions. The results indicate that rural households’ decisions regarding rural–urban student migration are jointly influenced by migration willingness and migration capacity. Only households with both migration willingness and migration capacity can actualize migration behavior. Migration willingness is derived from a cost–benefit analysis and involves joint decision-making by both parents, significantly influenced by parental personal characteristics and the student’s individual characteristics. The intermediate barriers to rural–urban student migration require certain migration capacities to be overcome, which are mainly influenced by family resource endowment and parental personal characteristics.