Product Tags and the Observability of Marketplace Enforcement: Evidence from DSA Transparency Data Bahadır Yüzbaşı and Serkan Benk Replication materials, version 1, 27 October 2026 REQUIREMENTS AND RUN Python 3.9 or later. The script uses only the Python standard library. Extract the complete archive, open a terminal in the extracted folder and run: python3 run.py --check python3 run.py The first command checks input hashes, cell count and statement-frequency total. The second reconstructs the nine result tables in results/tables and compares them byte for byte with reference/. No package installation is required. A run refuses to overwrite results/scope.json. To repeat, extract a fresh copy. The original workflow took a few seconds for arithmetic on a local laptop; execution time on other computers may differ. No random seed is needed. DATA AND SCOPE The data/prepared directory contains the frozen five-marketplace analytical snapshot and its exact common-support memberships and integer weights. There are 20,528 aggregation cells, representing a source count sum of 346,993,630 statements during September–November 2025. This total does not represent independently observed people, products, sellers or incidents. There is no regression, model fitting, resampling or hypothesis testing. The product-tagged population is a separate descriptive target. Undefined comparisons remain undefined. The public data preserve the original cells, values, source identifiers, matching fields and weights. DATA SOURCE European Commission, Digital Services Act Transparency Database. Download service: https://transparency.dsa.ec.europa.eu/explore-data/download Documentation: https://transparency.dsa.ec.europa.eu/page/documentation Data-package documentation: https://dsa.pages.code.europa.eu/transparency-database/dsa-tdb/data_sources.html The archive contains the selected frozen analytical snapshot rather than all monthly exports or the targeted raw-archive audit. Input and archive manifests allow the supplied files to be checked. Source-data reuse remains subject to the original provider's terms. See Supplementary Materials Guide for meanings, units, source-field definitions and the list of reference tables. OUTPUTS Nine CSV tables in results/tables, per-stratum outcome calculations and a calculation receipt. Frequency counts are source counts. Percentage columns end in _pct; differences are in percentage points. Empty numeric values are undefined, not zero. Overlapping pair counts must not be added together.