Carbon labels and rewards: driving sustainable consumer purchase decisions through incentive-based strategies

Promoting sustainable consumer behavior is vital for achieving climate goals. This study examines how carbon labels and rewards influence sustainable purchase intention (SPI) within green loyalty programs. Integrating the Theory of Planned Behavior (TPB) and Expectancy-Value Theory (EVT), it analyzes the effects of transparency in carbon labeling (TCL), pro-environmental attitude (PEA), subjective norm influence (SNI), perceived behavioral control (PBC), ease of reward redemption (ERR), and perceived reward value (PVR) on SPI, with loyalty to green wallet (LGW) as the behavioral outcome. A structured questionnaire was administered to 720 Thai consumers across five regions. Structural Equation Modeling (SEM) and multigroup analysis compared low-to-moderate and high environmental consciousness groups, revealing distinct motivational patterns. While TCL consistently strengthened PEA and SNI, only PVR and PBC significantly predicted SPI in both groups. Among low-conscious consumers, PEA strongly influenced SPI and LGW, whereas in highly conscious individuals, attitudinal effects weakened, and rewards played a greater role. This divergence reflects a “paradox of internalized sustainability,” where deeply committed individuals rely less on attitudes and more on incentives aligned with their values. The findings advance sustainability theory by integrating cognitive and motivational drivers into a unified model and provide practical guidance for designing carbon labeling and reward-based programs that enhance participation in low-carbon initiatives.