This open source repository holds the data and code underlying:
Lisa Matthias, Schares, E., Alperin, J. P., Butler, L.-A., Kuang, S., Schönfelder, N., & Haustein, S. 2026. Estimating global article processing charges paid to 14 publishers for open access between 2019 and 2025. [preprint link, once available]
Computational analysis was done with R.
The underlying article processing charge (APC) price list data is available to download and described in a companion data paper:
Matthias, L., Chavarro, D., Schares, E., Alperin, J. P., Rose, M., Frost, M., Camargo, F., Höfting, J., Butler, L.-A., Schönfelder, N., & Haustein, S. (2026). A dataset of article processing charges from 14 scholarly publishers, 2019–2025 [Data set]. Harvard Dataverse. doi: 10.7910/DVN/AZ985C
Matthias, L., Chavarro, D., Schares, E., Alperin, J. P., Rose, M., Frost, M., Camargo, F., Höfting, J., Butler, L.-A., Schönfelder, N., & Haustein, S. (2026). A dataset of article processing charges from 14 scholarly publishers, 2019–2025. [DOI]
This analysis combines two inputs — annual APC list prices (dataset above) and article publication counts from OpenAlex — to estimate global APC spend by publisher, year, and OA type. The repository is organized to reflect this pipeline, in order:
sql/— SQL query used to extract article counts per journal-year from the OpenAlex snapshot (via Google BigQuery).raw_data/— the raw export returned by the query above.processing/— R code used to process the raw export into a usable format.data/— processed datasets combining article counts with APC list prices, used as direct input to the analysis.results/— R Markdown files (and their rendered.mdoutput) that compute all figures, tables, and in-text statistics reported in the paper.figures/— figure files (.png/.svg) generated by the R Markdown files inresults/.
sql/
extract_article_counts_openalex_gbq.sql— query used to extract article counts by journal-year from the OpenAlex Walden snapshot in Google BigQuery.
raw_data/
BQ_export_Walden_fullAPCdataset_v5_297167rows.csv- raw BigQuery export file(s), prior to processing.apc_list_2025_5_analysis_v5_with_flatfees.csv— the analysis copy of the APC dataset (Matthias et al., 2026), which differs from the publicly available list-price dataset in the assumptions applied to non-flat-rate fees, as documented in the paper.
processing/
clean_process_BQ_exports_FullDataset.qmd- R code used to process the raw BigQuery export into the merged dataset used in analysis.
data/
12348_Gold&Hybrid_Walden_with_delta_filteredtoAPCdataset_withflatfees_and_APCs.csv— the processed BigQuery export, merged on ISSN-L and year to match the APC dataset.12348_journals_bypublisher_withflatfees_money_summary.csv— APC spend summary aggregated by publisher, OA type, and year.
results/
roara_apc_paper_analysis.Rmd/.md— main analysis: figures, tables, and in-text statistics reported in the paper, adjusted for inflation.roara_apc_paper_without_inflation_adjustment.Rmd/.md— nominal (unadjusted) equivalents of the main analysis, reported in the supplement.roara_apc_paper_publication_counts.Rmd/.md— publication count figures and tables reported in the supplement.
figures/
- All figure files generated by the R Markdown files above.