The concluding chapter highlights the key finding that local political incentives can cause powerful, systematic policy waves independent of top-down implementation campaigns. To demonstrate the theory’s applicability beyond China, this chapter examines air pollution trends in municipalities in Mexico. Like local political leaders in autocratic China pleasing their superiors for promotion, local politicians in democratic Mexico face incentives to cater to the desires of their constituents and bolster their political parties. Shen finds a significant peak in PM2.5 concentration level due to regulatory forbearance in municipalities during gubernatorial election years. The chapter demonstrates that across countries and regime types local leaders may opt for laxer regulation to achieve career goals. Yet, environmental policies are not always sacrificed to economic development, employment, and stability. This book’s findings are timely for policymakers and academics studying the determinants of effective regulation and illuminate a solution centering on cooperation between scientists and policymakers to effectively manage complex pollutants.