Middle-income economies in the world are under pressure to deal with a variety of environmental problems, such as industrial pollution, urban environmental issues, the deterioration of ecosystems, and global warming, while they are expected to simultaneously achieve high economic growth. In this context, they urgently need to leapfrog over environmental difficulties through progressive environmental management by utilizing their “latecomers' advantages” to the maximum extent possible. By utilizing the analytical framework of the environmental Kuznets curve (EK curve), this study examines whether or not middle-income economies actually enjoy latecomers' advantages in environmental management, depending on their stages of development. The study's main findings are as follows: (1) the outcomes of comparative analysis of the EK curves are generally consistent with the hypothesis that middle-income economies do enjoy latecomers' advantages; and (2) a regression analysis using cross-sectional data provides significant confirmation of the existence of latecomers' advantages for addressing the well known environmental problem of sulfur emissions in lower-middle-income economies.