What is happening with JSTOR coverage dates and embargoes?

We receive title lists from JSTOR that include two types of information: embargo restrictions and publication end dates. These embargoes are based on JSTOR’s moving wall model, while Ex Libris systems apply a rolling embargo model. Although similar in intent, these two models differ in how they calculate the availability of recent content, which can lead to discrepancies in coverage.

What’s the difference between a moving wall embargo and a rolling embargo?

A moving wall embargo is based on full calendar years. For example, a 3-year moving wall means that content is available only up to the end of the year, that is three years prior to the current year. If the current date is July 2025, content would be available through December 2021, and the next year’s content (2022) will become available in January 2026.
A rolling embargo, as applied in Ex Libris systems, is updated monthly. So a 3-year rolling embargo in July 2025 would allow content through July 2022, and in August 2025, content through August 2022 would become available.

How does this affect the content?

This mismatch between JSTOR’s embargo model and the model used by Ex Libris can result in visible differences between what Ex Libris shows as available and what is actually accessible on JSTOR’s platform.

To address this:

If JSTOR provides both an embargo and an end date in their title list, we use the latest possible coverage dates in order to present the most comprehensive access window to users.
If JSTOR provides only an embargo, we apply a more conservative rolling embargo to avoid displaying links to content that is not yet accessible on the JSTOR site, preventing broken links.

What’s next?

We acknowledge the current gap in embargo handling, and are evaluating the effort needed to develop a new process to resolve it. The prioritization of this development will depend on other enhancement requests in Idea Exchange.

• Article last edited: 30-Jul-2025