Understanding the efficacy of smallholder adaptation to changing environments is crucial to policy design. Past efforts in understanding whether, and to what extent, adaptation improves household welfare have faced some key challenges including: 1) endogeneity of adaptation; 2) localized results that are difficult to generalize; and 3) understanding whether the efficacy of adaptation depends on the reasons for adaptation (e.g. market conditions vs climate change). In this study we estimate effects of smallholder agricultural adaptation on food security, while addressing each of these three challenges. First, we identify and test instrumental variables based on neighbor networks. Second, we use a dataset that contains information from 5159 households located across 15 countries in Africa, Asia, and Central America. Third, we investigate whether adaptation that is motivated by changes in market conditions influences the efficacy of adaptation differently than adaptation motivated by climate change. Across our global sample, an average household made almost 10 adaptive changes, which are responsible for approximately 47 days of food security yearly; an amount nearly 4 times larger than is indicated if endogeneity is not addressed. But these effects vary depending on what is motivating adaptation. Adaptation in response to climate change alone is not found to significantly affect food security. When climate adaptation is paired with adaptation in response to changing market conditions, the resulting impact is 96 food secure days. These results suggest the need for further work on the careful design of climate change interventions to complement adaptive activities.

中文翻译：

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小农农业适应对粮食安全的影响：来自非洲、亚洲和中美洲的证据

了解小农适应不断变化的环境的功效对于政策设计至关重要。过去在了解适应是否以及在多大程度上改善家庭福利方面的努力面临一些关键挑战，包括：1）适应的内生性；2）难以泛化的局部结果；3) 了解适应的效果是否取决于适应的原因（例如市场条件与气候变化）。在这项研究中，我们评估了小农农业适应对粮食安全的影响，同时应对这三个挑战中的每一个。首先，我们基于邻居网络识别和测试工具变量。其次，我们使用的数据集包含来自非洲、亚洲和中美洲 15 个国家的 5159 个家庭的信息。第三，我们调查了由市场条件变化引起的适应对适应效果的影响是否与由气候变化引起的适应不同。在我们的全球样本中，平均每个家庭进行了近 10 次适应性改变，每年大约负责 47 天的粮食安全；如果不解决内生性问题，则该金额几乎是所指示的金额的 4 倍。但这些影响因激发适应的因素而异。仅凭对气候变化的适应并未发现对粮食安全产生重大影响。当气候适应与适应不断变化的市场条件相结合时，产生的影响是 96 个粮食安全日。这些结果表明需要进一步开展工作，仔细设计气候变化干预措施以补充适应性活动。