Offline constraints in online drug marketplaces: An exploratory analysis of a cryptomarket trade network.
Offline constraints in online drug marketplaces: An exploratory analysis of a cryptomarket trade network.
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DOI：
10.1016/j.drugpo.2018.03.016
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
L. Norbutas
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文献类型：
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作者：
L. Norbutas
加密市场，即促进毒品交易的非法匿名在线平台，已经在快速增长的研究机构中得到了分析。之前的研究发现，尽管风险增加，但加密市场卖家往往愿意在国际上运送非法药物。然而，关于与地理限制有关的不确定性和风险在多大程度上影响购买者的行为，进而影响全球在线毒品交易网络的结构，几乎没有信息。在本文中，我们分析了一个完整的加密市场交易网络的结构，重点讨论了买家和卖家地理集群的作用。方法我们使用公开的加密市场Abraxas，包括2015年463名卖家和3542名买家之间的市场交易。我们使用描述性社会网络分析和指数随机图模型（ERGM）来分析贸易网络的结构。结果网络毒品交易网络的结构主要受地理边界的影响。买家更有可能从一个国家的多个卖家那里购买，而避免从不同国家的卖家那里购买，这导致了很强的地理集群性。这种影响在大陆之间尤为强烈，而在欧洲国家则较弱。一小部分购买者（10%）占所有药品购买量的一半以上，而大多数购买者只购买一次。结论：尽管在线毒品交易网络能够为最终用户提供获得大量国际供应的途径，但它们仍可能受到线下（地理）限制的严重影响。加密市场可能比以前想象的更“本地化”，更不国际化。我们讨论了这种地理聚类的潜在解释和研究结果的含义。
BackgroundCryptomarkets, or illegal anonymizing online platforms that facilitate drug trade, have been analyzed in a rapidly growing body of research. Previous research has found that, despite increased risks, cryptomarket sellers are often willing to ship illegal drugs internationally. There is little to no information, however, about the extent to which uncertainty and risk related to geographic constraints shapes buyers’ behavior and, in turn, the structure of the global online drug trade network. In this paper, we analyze the structure of a complete cryptomarket trade network with a focus on the role of geographic clustering of buyers and sellers.MethodsWe use publicly available crawls of the cryptomarket Abraxas, encompassing market transactions between 463 sellers and 3542 buyers of drugs in 2015. We use descriptive social network analysis and Exponential Random Graph Models (ERGM) to analyze the structure of the trade network.ResultsThe structure of the online drug trade network is primarily shaped by geographical boundaries. Buyers are more likely to buy from multiple sellers within a single country, and avoid buying from sellers in different countries, which leads to strong geographic clustering. The effect is especially strong between continents and weaker for countries within Europe. A small fraction of buyers (10%) account for more than a half of all drug purchases, while most buyers only buy once.ConclusionOnline drug trade networks might still be heavily shaped by offline (geographic) constraints, despite their ability to provide access for end-users to large international supply. Cryptomarkets might be more “localized” and less international than thought before. We discuss potential explanations for such geographical clustering and implications of the findings.