Assessing market competition and vendors' size and scope on AlphaBay

Background: Since 2011, drug market participants have traded illegal drugs through cryptomarkets, a user-friendly infrastructure in which drug market participants can conduct business transactions. This study assesses market competition and the size and scope of drug vendors' activities on one of the largest cryptomarkets, AlphaBay, in order to better understand the challenges that drug vendors face when selling on this venue. Methods: Relying on data collected from AlphaBay, we calculate the degree of competition within the drug market using the Herfindhal-Hirshmann Index (HHI). We then follow a micro analytical approach and assess the size and scope of vendors' accounts. This is done by evaluating each vendor's market share over time using a group-based trajectory model (GBTM). Results from the GBTM are then used to assess vendors' exposure, diversity and experience based on their selling position in the market. Results: The HHI scores demonstrate that cryptomarkets offer a highly competitive environment that fits in a top-heavy market structure. However, the distribution of vendors' market share trajectories shows that only a small portion of vendors (referred to as high-level vendors) succeed in generating regular sales, whereas the majority of vendors are relegated to being mere market spectators with almost zero sales. This inequality is exacerbated by the aggressive advertising of high-level vendors who post many listings. Overall, product diversity and experience is limited for all market participants regardless of their level of success. We interpret these results through Reuter's work on traditional illegal markets, e-commerce studies and the growing field of cryptomarket research. Conclusion: We conclude that, while offering a new venue for illegal drug transactions, in many ways, the economics of cryptomarkets for drug dealing are consistent with Reuter's classic assessment of illegal markets and the consequences of product illegality that underlie it. Cryptomarkets conflicting features, a relatively open setting with relatively high barriers to entry and sales, shape the competitive, yet top-heavy market that emerges from our analysis. This creates a challenging environment for cryptomarket drug dealers. (C) 2018 Elsevier B.V. All rights reserved.