An Integrated SDT-TPB Model of Biogasoline Purchase Behavior: Empirical Evidence from the Vietnamese Market

Abstract

In recent years, Vietnam has implemented a roadmap to introduce biogasoline into consumption as a key strategy to reduce dependence on fossil fuels and environmental pollution. However, in reality, the rate of consumer acceptance remains relatively low and is trending downwards during the 2018-2025 period. This study aims to understand the mechanisms and factors influencing the biogasoline purchasing behavior of Vietnamese consumers. By integrating the Theory of Planned Behavior (TPB) and the Self-Determination Theory (SDT), the study examines how attitudes, intrinsic green motivations, and extrinsic green motivations influence biogasoline purchasing behavior, both directly and indirectly through purchase intentions. Data was collected through an online survey of 313 consumers from the North, Central, and South regions of Vietnam using a snowball sampling method. The Smart-PLS3 software was used to process survey data and examine the relationships between factors in the research model. The research results show that green extrinsic motivations were identified as the strongest predictor of purchase intention and directly impacted purchasing behavior, while green intrinsic motivations directly influenced purchasing behavior without significantly affecting purchase intention. The study provides practical insights for policymakers and energy providers in designing targeted strategies to promote consumption and support Vietnam's sustainable energy transition.