Econ Papers Daily / 期刊论文
小蠓虫，大后果：西非及以外地区可可授粉的部分衰退及其经济影响
Small Midges, Major Consequences: Partial Declines in Cocoa Pollination and Their Economic Impact in West Africa and Beyond
摘要
Cocoa production forms the backbone of West Africa's agricultural economy, sustaining smallholder farmers whose livelihoods depend on stable yields. Critical to these yields is the provision of pollination services by a few key species, notably, the minuscule Forcipomyia spp. While many studies have modeled the effects of complete pollinator collapse, the impacts of gradual declines remain little studied. In this study, we develop an integrated ecological–economic model that links pollinator abundance with cocoa yield, incorporating the global cocoa market and an economy‐wide framework for Ghana, one of the world's major cocoa producers. We examine scenarios in which declines in pollinator populations occur at regional, national, and supranational scales. Our analysis reveals that localized declines in pollinator populations detrimentally affect cocoa farmers and Ghana's national economy, with rural communities and low‐income households bearing a disproportionate share of the welfare losses. In contrast, widespread declines across West Africa trigger a “King effect” where rising global cocoa prices partially mitigate production losses, benefiting farmers while overall consumer surplus declines. These results highlight the necessity of conserving pollinator biodiversity to safeguard cocoa production and economic welfare at multiple scales.
中文摘要
摘要 可可生产是西非农业经济的支柱，支撑着依赖稳定产量维持生计的小农户。而关键传粉物种（尤其是微小的蠓属昆虫）提供的传粉服务对产量至关重要。尽管已有大量研究模拟了传粉者完全崩溃的影响，但传粉者逐渐减少的后果仍鲜有探讨。本研究构建了一个整合生态-经济模型，将传粉者丰度与可可产量相关联，并纳入全球可可市场及世界主要可可生产国加纳的整体经济框架。我们模拟了传粉者种群在区域、国家及超国家尺度上衰退的情景。分析表明：局部传粉者种群衰退对可可农户及加纳国民经济造成不利影响，其中农村社区和低收入家庭承受了不成比例的福利损失；而西非全境的广泛衰退则触发"国王效应"——全球可可价格上涨部分抵消了产量损失，使农户受益，但消费者剩余整体下降。这些结果凸显了保护传粉者生物多样性对保障多尺度可可生产与经济福利的必要性。