This study presents methods for assessing spillover effects between concurrent green initiatives, focusing on the U.S. Conservation Reserve Program (CRP) and Environmental Quality Incentives Program (EQIP), as well as China's Grain-to-Green Program (GTGP) and Forest Ecological Benefit Compensation (FEBC). The methods include multivariate and logistic regression, eigenvector spatial filtering to address spatial autocorrelation, and scenario modeling to project potential outcomes. The research aims to understand the collective impact of these initiatives on environmental goals. Findings show that EQIP enrollment reduces CRP enrollment, indicating a negative spillover effect. Scenario analysis suggests that reallocating EQIP land to CRP could save costs while maintaining total enrollment. Local evidence shows "double-dipping" in payments, where land is enrolled in multiple programs, leading to inefficiencies. In China, FEBC payments increase GTGP enrollment, but higher FEBC land areas decrease GTGP enrollment, indicating a complex spillover effect. The study also identifies various spillover effects, including Policy-Behavior, Behavior-Gain, Gain-Policy, Policy-Policy, Behavior-Behavior, and Gain-Gain effects, across different regions and initiatives. These findings highlight the importance of considering spillover effects in environmental policy design to enhance conservation effectiveness and sustainability. The study concludes that understanding and addressing these effects is crucial for maximizing the impact of concurrent green initiatives on environmental and socio-economic outcomes.This study presents methods for assessing spillover effects between concurrent green initiatives, focusing on the U.S. Conservation Reserve Program (CRP) and Environmental Quality Incentives Program (EQIP), as well as China's Grain-to-Green Program (GTGP) and Forest Ecological Benefit Compensation (FEBC). The methods include multivariate and logistic regression, eigenvector spatial filtering to address spatial autocorrelation, and scenario modeling to project potential outcomes. The research aims to understand the collective impact of these initiatives on environmental goals. Findings show that EQIP enrollment reduces CRP enrollment, indicating a negative spillover effect. Scenario analysis suggests that reallocating EQIP land to CRP could save costs while maintaining total enrollment. Local evidence shows "double-dipping" in payments, where land is enrolled in multiple programs, leading to inefficiencies. In China, FEBC payments increase GTGP enrollment, but higher FEBC land areas decrease GTGP enrollment, indicating a complex spillover effect. The study also identifies various spillover effects, including Policy-Behavior, Behavior-Gain, Gain-Policy, Policy-Policy, Behavior-Behavior, and Gain-Gain effects, across different regions and initiatives. These findings highlight the importance of considering spillover effects in environmental policy design to enhance conservation effectiveness and sustainability. The study concludes that understanding and addressing these effects is crucial for maximizing the impact of concurrent green initiatives on environmental and socio-economic outcomes.