A paradox of economic benefit and social equity of green space in megacity: Evidence from Tianjin in China

Urban green space (UGS) plays a crucial role in socio-ecological systems and has been recognized as an important factor in promoting sustainable cities and communities. Although a few studies have proposed a paradox of the incompatibility of economic benefit and social equity in UGS, the mechanisms through which the economic benefits of UGS interact with social equity have not been adequately demonstrated in developing countries. Here, we employ multi-source geographic information and 1,559 residents survey data to investigate not only the economic benefit of UGS in the housing prices market from a macro perspective, but also the social inequity issues resulting from the housing choices of different social classes under "UGS economic benefit" from a micro perspective. Results reveal that the economic value premium of UGS in the housing market triggered a differentiation effect in housing prices, subsequently influencing housing preferences among various social classes, thus intensifying social residential segregation. This phenomenon underscores the emergence of the green space paradox. Moreover, the phenomenon of the UGS paradox has emerged in megacities of developing countries, where UGS is gradually being occupied by social elites, while vulnerable groups remain marginalized. These findings provide valuable insights into the planning layout of UGS in global high-density built-up areas that a small and decentralized UGS layout will be more economically efficient and socially equitable than a large and centralized UGS layout.