Urbanization under globalization: How does the Belt and Road Initiative affect urbanization levels in participating countries

China's Belt and Road Initiative (BRI) presents the world with a new era of inclusive globalization, which will shape urbanization patterns globally. This study considered the launch of BRI as a quasi-experiment, where we evaluated the BRI's impact on urbanization by way of difference-in-differences (DID) and propensity score matching (PSM) methods. The results showed that the BRI exerted a significantly negative effect on urbanization in its first three years. Its positive effect emerged from the fifth year onwards, indicating that the BRI's positive effect on urbanization required a period of practical experience. Heterogeneous analysis and placebo test were also conducted to verify the robustness of the model. The effects in low-income countries were revealed to have been much greater than in high-income countries, meaning the BRI had been conducive to promote local urban growth in underdeveloped economies. Finally, the geographical detector model was introduced to discuss the influencing mechanism of urbanization in BRI and non-BRI countries, showing external factors were the prominent driving forces in BRI countries, whereas internal drivers played an important role in non-BRI countries. Our findings indicated that the implementation of the BRI contributed to building global economic growth and supporting a shared future.