Identifying the Key Drivers in Energy Technology Fields: The Role of Spillovers and Public Policies

This study investigates the salient roles of knowledge spillover and environmental policies on clean technology innovation. Employing a panel vector autoregressive model (PVAR) and connectedness network analysis with a comprehensive longitudinal dataset comprising 100 million patent documents across 26 countries, the study identifies clean technology fields that are most efficient in driving innovation and subsequently quantifies the spillover effects for each field. The impact of public environmental policies and regulations on clean technological innovations is also examined in depth. The results reveal that clean innovation is a complex and nuanced system, with significant knowledge spillovers occurring within and across energy and non-energy-related clean technology fields. The results also show that environmental policies significantly influence clean innovation, with technology support and adoption support policies having the most substantial impact. Furthermore, the results reveal that the impact of market-based policies on clean innovation is weaker than that of non-market-based policies, which is an important consideration for policymakers. The findings hold significance for policymakers in addressing sustainability goals and their implications.