Insights from spatial Markov chain and dynamic QCA into the spatiotemporal evolution and configurational pathways of eco-efficiency in China’s coastal megaregions

Why city clusters by the sea matter

China’s big coastal city clusters are the powerhouses of its economy—and some of the most stressed environments on Earth. This study asks a simple but urgent question: how can these fast-growing regions keep creating jobs and wealth while using fewer resources and causing less pollution? The authors focus on “eco-efficiency,” meaning how much economic and social benefit a region can produce per unit of environmental cost, and they trace how this balance has changed over time and space along China’s coast.

Measuring more gain with less pain

To track eco-efficiency across 96 cities in five major coastal megaregions from 2011 to 2022, the researchers build a detailed scorecard. On the input side they count people, investment, land, water and electricity. On the output side they reward both income and urban green space—parks and vegetation that improve quality of life. They also subtract three major pollutants, including carbon dioxide. A specialized efficiency model then compares each city with the best performers, giving a score that reflects how well it turns resources into prosperity with minimal damage.

Rising performance and coastal hot spots

The results show encouraging progress. On average, eco-efficiency in all five megaregions rose over the decade, though not smoothly. Around 2016–2017, scores dipped as China launched an unusually tough round of environmental inspections that forced many dirty factories to close before cleaner technologies were fully in place. After that shock, the trend turned upward again. The Pearl River Delta in the south consistently led the pack, followed by the West Coast of the Taiwan Strait and the Shandong Peninsula, with the Yangtze River Delta and the Beijing–Tianjin–Hebei region lagging. Maps reveal a clear pattern: higher eco-efficiency along the coast than inland, and over time, isolated “bright spots” of good performance merged into continuous high-efficiency belts.

Patterns that spread across space

Eco-efficiency does not change at random. Using tools that track how cities move between low and high performance groups, the authors find strong “inertia”: cities are far more likely to stay in their current category than to jump up or down. The very best and very worst cities are especially stable, forming what the authors call “clubs.” Yet geography still matters. When a low-efficiency city is surrounded by high-efficiency neighbors, it has a much higher chance of improving than if it sits among other laggards. In other words, cleaner practices, better planning and greener industries tend to spill over city borders, helping nearby places escape their old, more polluting growth paths.

Three roads to greener growth

Beyond mapping where eco-efficiency rises or falls, the study asks what combinations of forces actually drive success. Drawing on the idea of “institutional logics”—the different ways government, markets and technology shape behavior—the authors test how seven factors work together rather than one by one. They find no single magic lever. Instead, high eco-efficiency emerges from three broad patterns. In some cities, market forces dominate: openness to global trade, strong green finance and a shift toward cleaner service industries reinforce each other. In others, strict environmental rules, coupled with open markets and green finance, create a government–market partnership that pushes firms to clean up. A third group relies on a blend of markets and technology, where green finance fuels digital tools and green innovation that cut waste and emissions.

What this means for people and policy

For non-specialists, the takeaway is that greener growth in coastal megaregions is both possible and already happening—but it depends on smart mixes of policy, investment and innovation rather than a single fix. Southern and eastern coastal cities have turned themselves into leaders by combining economic openness with financial support for low-carbon projects and, in many cases, strong public oversight and new technologies. The authors argue that other regions can catch up by tapping spillover benefits from these leaders, building cross-city cooperation on environmental projects and tailoring their own blend of government action, market incentives and technological change. Done well, that recipe can deliver city regions where cleaner air, healthier ecosystems and robust economies reinforce each other instead of being at odds.

Citation: Di, J., Wang, Y. Insights from spatial Markov chain and dynamic QCA into the spatiotemporal evolution and configurational pathways of eco-efficiency in China’s coastal megaregions. Sci Rep 16, 10277 (2026). https://doi.org/10.1038/s41598-026-40460-3

Keywords: ecological efficiency, coastal megaregions, green finance, urban sustainability, China city clusters