Embracing the Impact: Understanding the Decline of Impact Factors in INFORMS Journals and the Future of OR/MS Publishing

In July 2023, we reported on the noticeable decline in impact factors across INFORMS journals – an average decline of 12% – reversing the previous upward trend. We attributed this decline to changes in impact factor methodology and predicted that the trend would continue: “The decline could continue for many journals next year until impact factors stabilize in 2025” [1].

On June 20, 2024, Clarivate released the 2023 edition of its impact factors, confirming our predictions, particularly for several flagship INFORMS journals (see Figure 1).

Of the 12 INFORMS journals tracked by Clarivate, eight have experienced declines in their impact factors. Over the past two years, seven of these journals have seen their impact factors decline by more than 25%. In particular, the three leading operations research and management science (OR/MS) journals – Management Science, Manufacturing & Service Operations Management (M&SOM) and Operations Research – have experienced some of the largest declines, with their impact factors falling by 25%, 32% and 44%, respectively.

INFORMS journals are not alone in this battle and have arguably fared better than many of their peers. According to an analysis by Matthew Walls, director of publications at INFORMS, the impact factor of the entire OR/MS category fell by 23.7% last year, which is more than the 16.6% decline observed in INFORMS journals during the same period.

We encourage readers interested in understanding the reasons for these declines to read our July 2023 report and discussion on INFORMS Connect [1]. In brief, Clarivate’s impact factor measures the average number of citations received by each published article. The key questions are which articles should be included in the calculation and the time frame over which citations should be considered. Currently, Clarivate considers the number of citations received in the past year for articles published in the previous two years. For example, the 2023 impact factor for a journal is calculated by dividing (1) the total number of citations in 2023 for the journal’s cited articles from 2022 and 2021 by (2) the total number of cited articles published in 2022 and 2021.

Before 2021, the impact factor was calculated based on citation data from the volume year, meaning that items not associated with a printed issue were excluded. However, starting with the 2020 impact factor (released in 2021), the calculation shifted to using citation data from the publication year. This change meant that early-access content was included in the numerator of the 2020 impact factor calculation. Under the phased-rollout approach, early-access content would be included in both the numerator and denominator of the calculation starting as early as 2022 (for the 2021 impact factors).

The field of OR/MS, like many other social science disciplines, has long publication cycles. Consider a paper (hereafter “Paper A”) that is published online in Management Science in 2022 but is not included in a volume until late 2023. The paper will gain wider attention – beyond the small group of scholars who are familiar with its unpublished version – when this online publication takes place. Suppose Paper A is immediately cited in a newly written paper (hereafter “Paper B”). At the current rate of publication, it is highly unlikely that Paper B will be published before the end of 2023. If Paper B is published in 2023, it is more likely to appear online than in a printed volume.

The old Clarivate method helped mitigate the impact of the publication cycle. Because Paper A will not be published in a volume in 2021 or 2022, it will not be included in the impact factor calculation in 2023. The first time it would enter the impact factor calculation would be in 2025. By that time, Paper B would likely have been published in print and thus contribute to the impact factor. Therefore, the old method was generally beneficial for disciplines with long publication cycles.

However, the new Clarivate method no longer distinguishes between whether a paper was published online or in a printed volume. A paper’s year of publication is now considered to be when it is first published online. In the previous example, Paper A would be included in the calculation of impact factors for 2023. However, because Paper B is unlikely to be published before the end of 2023, Paper A’s citations would not be counted, potentially lowering the journal’s overall impact factor.

Clarivate has implemented a phased adoption of this method. Last year, a combination of old and new methods was used: publications from 2021 were based on the year they appeared in a volume, whereas publications from 2022 were based on the year each article was first published online. This year (2024) marks the first full implementation of this method in which all publication years are determined by the online publication date of each article.

Looking Ahead

What lies ahead for INFORMS journals and OR/MS publishing in general? We offer the following general thoughts in the hope of stimulating meaningful discussion within our community.

First, we need to accept reality without sounding or acting defensive. Two years ago, five INFORMS journals had impact factors greater than 5. Today, none have that distinction. A decline is a decline. Regardless of the reasons for this decline, we must face the reality that it cannot be solely attributed to changes in methodology. Instead, we should focus on learning from the data, which highlights broader challenges we face in adapting to the evolving landscape of scholarly publishing.

Second, we need to understand the cause of the decline. As previously shown, long publication cycles are a significant contributing factor. A high proportion of citations to articles in INFORMS journals come from other INFORMS journals. Because most INFORMS journals have long lead times between submission and acceptance, it is critical to reduce these lead times by systematically reforming our review processes across all INFORMS journals. This will require a coordinated effort by the entire INFORMS community. One example is the two-round policy initiated in Manufacturing & Service Operations Management under Professor Christopher Tang [2], which has since been adopted by Management Science and several other INFORMS journals. Another example is Management Science, which, under the editorship of the first author of this article (Simchi-Levi), implemented a “Fast Track” submission process to encourage a short review cycle that is aligned with some of the most impactful general-interest journals such as Science and Nature, and serves as “a platform for the most innovative and impactful papers and to disseminate them in a timely manner that reaches beyond our community” [3]; the average time to first decision for Fast Track papers was about 30 days, significantly less than the time for regular papers. Since the introduction of Fast Track, several other INFORMS journals (e.g., Marketing Science and Operations Research) introduced similar submission channels.

Third, we must ensure that publications in INFORMS journals are widely disseminated and frequently cited in other OR/MS journals and journals in other disciplines. INFORMS members conduct timely research on critical issues such as artificial intelligence, supply chain management, climate change, cybersecurity, logistics and transportation. These topics are of interest to a wide range of stakeholders beyond the current INFORMS community. It is critical that our journal publications, known for their rigor, high quality and thorough review, reach a wider audience rather than reinforce an echo chamber. Achieving this will require a concerted, INFORMS-wide effort.

The world has moved on, and we risk being left behind if we do not follow suit. As a community, we have always embraced change and often benefited from it. There is every reason to believe that this time will be no different.

Acknowledgment: This article benefited from the thoughtful feedback of Professor Christopher Tang, Vice President of Publications, and Matthew Walls, Director of Publications, both at INFORMS.

References

1. Simchi-Levi, David and Tinglong Dai, 2023, “Unraveling the mystery of impact-factor declines in most of INFORMS journals,” INFORMS Open Forum, INFORMS Connect, July 11, https://bit.ly/informs23if.
2. Tang, Christopher S., 2015, “Can review less generate more progress?,” From M&SOM Journal Editor, April 1, https://bit.ly/mstworound.
3. Simchi-Levi, David, 2018, “Fast track submission in Management Science,” INFORMS Open Forum, INFORMS Connect, February 23, https://bit.ly/msftrack.