Addressing Endogeneity in Climate-Smart Technology Adoption: The Role of Extension and Credit among Vanilla Farmers in Morogoro region

Climate-smart agricultural (CSA) technologies are vital for enhancing the climate resilience of high-value, climate-sensitive crops like vanilla in Sub-Saharan Africa. While institutional support through agricultural extension and formal credit is widely promoted to drive CSA adoption, empirical evidence of their causal impact is often confounded by endogeneity from farmers' non-random access to these services. This study investigates the determinants of CSA technology adoption among smallholder vanilla farmers in Tanzania's Morogoro region, explicitly addressing the endogeneity of extension access. Employing an instrumental variable probit (IV-Probit) model with data from 270 farmers, the study uses distance to extension offices and access to demonstration plots as instruments. The results confirm that access to extension services is endogenous and is the most significant driver of adoption. Female farmers, married households, access to credit, off-farm income, livestock ownership, higher income, and a risk-tolerant attitude also significantly increase the likelihood of adoption. The findings underscore that adoption is driven by a combination of robust institutional support, economic capacity, and household characteristics. The study concludes that scaling CSA in perennial crop systems requires integrated policies that strengthen targeted, gender-responsive extension systems, improve financial inclusion, and address behavioral barriers to reduce investment risks and foster sustainable climate adaptation.