Despite concerted efforts, achieving the goal of universal food security remains challenging. Food security interventions occur at different levels of systemic depth. Some interventions target visible supply-side gaps, while others focus on deeper systemic problems in the food system. Here, we used a leverage points perspective to ask how multiple types of more superficial (shallow) and more fundamental (deep) interventions in the food system interact. Focusing on a case study in southwestern Ethiopia, we examined (1) recent changes in formal and informal institutions related to food security; (2) the effects of formal and informal institutions on the food system at different levels of systemic depth (i.e., on parameters, feedbacks, design, and intent); and (3) issues of institutional interplay between formal and informal institutions. We surveyed 150 rural households and analyzed key policy documents. Both formal and informal institutions were perceived to improve food security. However, at the intent level, formal institutions primarily aimed to enhance food supply, while informal institutions additionally sought to build trust among farmers. At the design level, formal interventions targeted information flow through a newly created agricultural extension system, while informal institutions facilitated labor sharing and communication. In terms of institutional interplay, new formal institutions had partly undermined pre-existing informal institutions. We conclude that both visible supply-side gaps and deeper drivers of food insecurity should be targeted through food security interventions. Interventions need to be cognizant of potentially unexpected ways of institutional interplay, especially between formal and informal institutions.

尽管作出了共同努力，实现普遍粮食安全的目标仍然充满挑战。粮食安全干预措施发生在系统深度的不同级别。一些干预措施针对可见的供应方差距，而其他干预措施则针对食品系统中更深层次的系统性问题。在这里，我们使用杠杆角度来询问食品系统中多种类型的更浅（浅）和更基本（深）的干预措施如何相互作用。我们以埃塞俄比亚西南部的一个案例研究为重点，研究了（1）与粮食安全有关的正式和非正式机构的最新变化；（2）正式和非正式机构对粮食系统在不同系统深度上的影响（即对参数，反馈，设计和意图）的影响；（3）正式和非正式机构之间的机构相互作用问题。我们对150个农村家庭进行了调查，并分析了重要的政策文件。正式机构和非正式机构都被认为可以改善粮食安全。但是，就意图而言，正式机构主要旨在增加粮食供应，而非正式机构还试图在农民之间建立信任。在设计一级，正式干预的目标是通过新建立的农业推广系统进行信息流动，而非正式机构则促进了劳动共享和交流。就机构之间的相互作用而言，新的正式机构已部分破坏了先前存在的非正式机构。我们得出结论，应该通过粮食安全干预措施来应对明显的供应方差距和更深层次的粮食不安全驱动因素。