Abstract: Community-based development (CBD) projects have long emphasized a bottom-up approach. For CBD initiatives to succeed, communities must harness their social capital, organize themselves, and actively engage in development processes. While CBD proponents highlight the promotion of social capital through community-based projects, critics argue that their effectiveness relies on pre-existing levels of trust, trustworthiness, and community interactions. To contribute to this debate, we investigate the selection bias regarding social capital induced by the recruitment strategy of an NGO in Zimbabwe. We look at differences between selected beneficiaries and non-beneficiaries in terms of pro-social behaviors, measured by incentivized games, and in terms of social networks. We also use this information to test whether being part of the same networks translates into increased trust, altruistic behaviors, and willingness to participate in collective action. Our study, conducted in 2022 in the rural district of Murehwa, Zimbabwe, comprised a survey and lab-in-the-field experiments (trust game, public good game, dictator game) involving 341 subjects. Findings showed that selected beneficiaries exhibit higher network density than non-beneficiaries. However, except for a partial experimental measure of trustworthiness, we observed no significant differences in prosocial behavior between the two groups before project implementation. The results suggest that although selected beneficiaries are more socially connected, they do not exhibit higher prosocial behaviors. These findings shed light on the common selection process used by development agencies and the inherent bias they introduce. To address this bias, development agencies should reconsider recruitment strategies that prioritize existing social ties, as they may unintentionally exclude less-connected community members. Instead, they should explore alternative selection approaches, such as the use of field data to ensure inclusiveness. Additionally, integrating trust-building activities at the beginning of projects could enhance cooperation among participants.

Abstract: Decades of research have demonstrated the agronomic and environmental benefits of sustainable intensification (SI) practices, such as crop residue mulching and legume diversification. However, little is known about how farmers value specific characteristics of SI practices and the trade-offs they are willing to accept. This study addresses this gap by employing a Discrete Choice Experiment (DCE) in the Murehwa district of Zimbabwe. In 2022, 271 households participated in the DCE, which included attributes such as fodder availability, legume production, labor requirements, fertilizer use, and a subsidy. Using a mixed logit model, we find that farmers highly valued legume production, indicating a preference for practices that incorporate legumes into cropping systems. Farmers also placed significant importance on maize residues for fodder, revealing a key trade-off between using residues as fodder or mulch. Increased labor requirements were viewed unfavorably, indicating a potential barrier to the adoption of labor-intensive practices. Furthermore, the study shows that farmers' preferences vary depending on their socio-demographic factors, with age and gender playing significant roles. Our analysis provides estimates of the subsidy levels needed to incentivize SI practices adoption and insights into the socio-economic profiles of early and late adopters.

Abstract: The adoption of sustainable land-use systems (SLUS) remains low among smallholder farmers in Sub-Saharan Africa, mainly due to immediate costs and risks outweighing short-term benefits. This study examines how different payments for environmental services (PES) mechanisms can incentivize SLUS adoption among smallholder farmers in Zimbabwe, assuming a critical mass adoption would enhance environmental services. Using a framed lab-in-the-field experiment with 588 farmers, we modeled SLUS adoption as a threshold public good game and compared three PES mechanisms: individual payments unconditional on reaching an adoption threshold, collective payments conditional on reaching adoption threshold, and a combined approach incorporating both payment types. We also investigated policy framing effects on adoption decisions and explored prosocial and risk preferences’ role in decision-making. Results show only the combined payment scheme successfully achieved the SLUS adoption threshold. When the same payment structure was implemented without explicit explanation of the additional payment, contributions dropped to control group levels, highlighting policy framing’s crucial role. Social preferences and risk attitudes showed minimal correlation with adoption decisions, although farmers exhibiting other-regarding preferences in the dictator game contributed more to the threshold public good game. These findings advance our understanding of PES design by demonstrating that combining individual and collective payments can overcome coordination challenges in SLUS adoption, while emphasizing clear communication in program implementation.