A significant proportion of trade in Africa takes place informally. In this paper we postulate that informal trade is more sensitive to securityrelated trade costs than formal trade. To test this hypothesis, we combine unique aggregated survey data on Uganda's informal crossborder trade with formal customs data and exploit the spatial and time variation of the South Sudanese civil war to causally identify the impact of conflict on different types of trade. Our preferred estimates suggest that the civil war reduced Uganda's informal exports to South Sudan by as much as 80%, compared to an estimated effect of 12% for formal exports. Further, we show that the impact of the conflict on formal exports is driven entirely by a reduction of industrial goods exports while exports of agricultural products continued to flow, presumably reflecting necessities in consumption for which willingness to pay is high. Taken together our results are consistent with the hypothesis that security-related trade costs have heterogeneous effects on different types of international trade.

中文翻译：

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贸易、冲突和非正式：来自南苏丹内战的证据

非洲的很大一部分贸易是非正式进行的。在本文中，我们假设非正式贸易比正式贸易对安全相关的贸易成本更敏感。为了验证这一假设，我们将乌干达非正式跨境贸易的独特汇总调查数据与正式海关数据相结合，并利用南苏丹内战的空间和时间变化来因果确定冲突对不同类型贸易的影响。我们首选的估计表明，内战使乌干达对南苏丹的非正规出口减少了 80%，而正规出口的估计影响为 12%。此外，我们表明，冲突对正规出口的影响完全是由于工业品出口减少而农产品出口继续流动，大概反映了支付意愿很高的消费必需品。综上所述，我们的结果与安全相关的贸易成本对不同类型的国际贸易产生不同影响的假设是一致的。