Collaborative environmental governance (CEG) is a tripartite process that engages the government, private sector, and general public in decision-making related to environmental challenges, focusing on fostering more sustainable and efficient solutions. Understanding the specific factors influencing the degree of CEG presents a significant challenge, particularly in developing countries. This study aims to identify and assess the socio-economic determinants affecting the degree of CEG in Thailand, a representative developing country. Utilizing robust panel data models, which are well-suited to handle the complex variability of socio-economic factors, we analyzed provincial-level data from 2017 and 2019. Our findings revealed the associations between the degree of CEG and variables such as the internet access divide, economic activities, income inequality, and budget allocations for environmental activities. This research fills critical gaps in our understanding of how these determinants shape collaborative governance efforts, offering novel insights that challenge existing paradigms and providing actionable recommendations for policymakers striving to enhance environmental governance in developing regions.