Can producer groups improve technical efficiency among artisanal shrimpers in Nigeria? A study accounting for observed and unobserved selectivity

Abstract

Abstract It is widely recognized that participation in producer groups is advantageous for smallholders who must deal with complex production and marketing constraints and dynamic business environments. However, available data on this process are scarce in the fishery sector, while existing evidence is limited by smallholders’ potential self-selection into producer groups. This study, therefore, examined the selectivity-corrected role of fisher groups in improving shrimpers’ technological and technical efficiency. Using the latest primary data from artisan shrimpers in Nigeria, we applied propensity score matching and Greene’s selectivity stochastic production frontier model to control for selection bias from both observable and unobservable factors. Empirical results from our metafrontier approach show that technical efficiency scores for members tend to be overestimated if selectivity is not properly controlled. However, the technical efficiencies and productivities of members were significantly higher regardless of how biases were corrected, implying that participation in fisher groups is positively related to increases in shrimpers’ capture and technical efficiency. Further findings suggest that current artisanal fisher groups are “production-oriented” as they ensure that members access vital shrimping inputs at lower costs. With declining returns to scale for members, the study concludes that without public and private support for collective action in the fishery sector, membership in artisanal fisher groups may not lead to significant improvement in shrimpers’ productivity. The study discusses several recommendations on how collective action can be further encouraged and developed among artisan fishers.

Keywords

• Technical efficiency
• Greene’s stochastic production frontier
• Propensity score matching
• Selection bias
• Nigerian fisher group
• Artisan fishers