Addressing pre-harvesting sugarcane burning in Thailand: A quasi-experimental study of monetary incentive

In Thailand, the recurring environmental issue of high PM2.5 concentrations from December to April is partly due to pre-harvest sugarcane burning. This practice severely impacts the environment, economy, and public health. To combat this, the Thai government aims to eliminate pre-harvest sugarcane burning by 2024 through a voluntary monetary incentive scheme. This study employs a quasi-experimental approach in eight Thai regions to evaluate the policy's effectiveness. Using the strategy method, this paper aims to determine the Minimum Acceptable Price (MAP) and Willingness to Accept (WTA) for farmers to switch from selling burned to fresh sugarcane. Findings indicate that the positive incentive of THB 120 per ton for fresh sugarcane influences 88.77% of farmers to cooperate. To achieve over 90% compliance, the subsidy should increase to THB 150 per ton, requiring an additional budget of approximately THB 2,100 million per crop season. Conversely, the negative incentive measure, which follows the "polluter pays principle," involves deducting THB 30 per ton from the sale price of burned sugarcane. This results in 82.17% of farmers switching to fresh sugarcane. To reach the 90% effectiveness target, the deduction should increase to THB 50 per ton, potentially leading to a fine collection of THB 378.85 million based on the previous season's production. This study's findings will inform future policy adjustments and contribute to academic knowledge on farmers' responsiveness to public policies.