Declining subjective well-being disparities concurrent with urbanization in China.

While urbanization has significantly reshaped cities globally, its complex multidimensional impacts on subjective well-being (SWB) remain poorly understood. We develop an integrated ecological and social framework using 2.92 million street view images and assess its relationship to urban residents' SWB derived from 5.3 million social media posts across 107 Chinese cities. Our study reveals a notable decline in SWB disparities, with a significant increase in the lowest SWB class and a corresponding decrease in the highest class. Urban ecological factors, such as vegetation coverage and street ecological index, are positively correlated with SWB in lower well-being populations but negatively associated with SWB in higher well-being groups. Conversely, urban social and economic determinants, including population density and service accessibility, exhibit opposite trends, revealing the multifaceted and complicated mechanisms through which urbanization processes influence residents' SWB. This research underscores the critical role of urban environments in mitigating SWB disparities and suggests that policies enhancing environmental quality and social equity are crucial for fostering healthier, more equitable cities.