Abstract This study provides evidence that infrastructure investment can encourage economic activity through illicit pathways. I examine this relationship in the context of Afghanistan, where I show that the construction of the country's largest modern infrastructure project, a 2,200 kilometer highway known as the A1 or Ring Road, led to significant increases in local opium cultivation over the past decade. Estimates from a two-way fixed effects model that exploits spatial and temporal variation in district-level poppy cultivation and proximity to the road suggest that the introduction of a highway to a district is associated with a 650 hectare increase in poppy cultivation in the subsequent year. This cultivation increases the longer a district has access to the road: Production in the second and third years rises by 750 and 900 hectares over pre-highway levels, respectively. Estimates also suggest that improved highway access leads Afghan farmers to substitute away from the production of legal crops towards opium, and that more farmers grow opium as their primary income-generating crop. These findings suggest that in nations where the rule of law is limited and opportunities for legal livelihoods remain scarce, investments in physical infrastructure can inadvertently incentivize illegal economic activity.

中文翻译：

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基础设施的意外危害：阿富汗的鸦片和道路建设

摘要 本研究提供证据表明基础设施投资可以通过非法途径鼓励经济活动。我在阿富汗的背景下研究了这种关系，在那里我展示了该国最大的现代基础设施项目的建设，一条被称为 A1 或环路的 2,200 公里高速公路，导致了过去十年当地鸦片种植的显着增加。双向固定效应模型利用地区级罂粟种植和道路邻近性的时空变化进行的估计表明，将高速公路引入一个地区与随后一年罂粟种植面积增加 650 公顷有关. 一个地区通向道路的时间越长，这种栽培就会增加：第二年和第三年的产量分别比高速公路前的水平增加了 750 和 900 公顷。估计还表明，高速公路通道的改善导致阿富汗农民从合法作物的生产转向鸦片，更多的农民将鸦片作为主要的创收作物种植。这些调查结果表明，在法治有限且合法谋生机会仍然稀缺的国家，对有形基础设施的投资可能会在不经意间刺激非法经济活动。