Trends in the availability and types of drugs sold on the internet via cryptomarkets, June 2022 - May 2023

This code then informs the crawlers of the location of the specified drug categories, allowing the crawler to then iterate through the indexed pages of each of those categories. [...] In the current bulletin, drug categorisation on the data from 1st February 2020 onwards were improved with the addition of new drug terms for rule-based classification and in the algorithm for the final assignment of listings to drug categories (see section 5.1.2.3). [...] The majority of these listings used the more common or well-known drug as the descriptor of the drug being sold in the listing. [...] Creation of twice monthly snapshots from historical data For the weekly data from before 1st August 2022, twice monthly snapshots of the cryptomarket data were taken from the first week of data in each of the two-week period starting on the 1st and 15th of each month. [...] Relative percent difference in percentage of listings of a Level 2 drug between individual markets and overall market The relative difference in market share of a particular drug (expressed as a percentage of total listings in the market) between an individual market and the overall market is: Percentage of drug in individual market− Percentage of drug in overall market × 100% Percentage of drug i.