A tipping point for open citation data

TL;DR

Open citation data reaching a critical mass has transformed the scientific data ecosystem, enhancing transparency, policy-making, and discoverability, marking an irreversible shift towards openness.

Contribution

This paper documents the crossing of a pivotal threshold in open citation data, highlighting its impact on the scientific ecosystem and guiding future open data initiatives.

Findings

Public-domain citation databases exceeded one billion citations in 2021.

The flood of open data has diminished the advantage of closed citation databases.

This shift is likely irreversible, influencing future open data efforts.

Abstract

Open citation data can improve the transparency and robustness of scientific portfolio analysis, improve science policy decision-making, stimulate downstream commercial activity, and increase the discoverability of scientific articles. Once sparsely populated, public-domain citation databases crossed a threshold of one billion citations in February 2021, during the COVID-19 pandemic. Shortly thereafter, the threshold of one billion public-domain citations from the Crossref database alone. Since the relative advantage of withholding data in closed databases has diminished with the flood of public-domain data, this likely constitutes an irreversible change in the citation data ecosystem. The successes of this movement can guide future open data efforts.