The effect of agricultural input choices on food security outcomes in rural Southeast Asia

Purpose. This study examines whether the adoption of organic fertiliser improves household food security in rural Southeast Asia, with a comparative focus on Vietnam and Thailand. Methodology. The study uses household-level data from the Thailand–Vietnam Socio-Economic Panel (TVSEP) to analyse the relationship between organic fertiliser adoption and household food insecurity experiences. Food security is measured through eight experience-based indicators capturing anxiety about food access, dietary inadequacy, meal reduction, food shortages, and hunger. To address selection bias and potential endogeneity in adoption decisions, the study applies Propensity Score Matching (PSM) and Instrumental Variable (IV) estimation, using leave-one-out community-level organic fertiliser adoption rates as instruments. Results. The findings show that organic fertiliser adoption leads to significant reductions in several dimensions of household food insecurity in Vietnam. The PSM estimates show that organic fertiliser adoption is associated with significantly lower food insecurity in seven of the eight indicators in Vietnam. IV estimates confirm significant reductions in six indicators (FIE2–FIE7). In Thailand, five food-insecurity indicators are significant in the unmatched comparison, but only meal skipping (FIE4) remains statistically significant after matching, and none of the IV estimates is statistically significant. These results suggest that the food security benefits of organic fertiliser adoption are context-specific and depend on household vulnerability, production conditions, and institutional environments. Originality. This study contributes to the literature by directly linking organic fertiliser adoption with multidimensional food insecurity experiences rather than relying solely on productivity, income, or expenditure outcomes. It also provides comparative evidence from Vietnam and Thailand, showing that the welfare effects of organic input adoption are not uniform across rural Southeast Asian contexts. Practical implications. The findings suggest that promoting organic fertiliser should not be treated as a stand-alone intervention. To improve household food security, policies should combine organic fertiliser adoption with agricultural extension services, farmer training, peer-learning mechanisms, and targeted support for resource-constrained smallholders.