University mergers and ranking impact: what happens when institutions combine

The rationale behind university mergers

University mergers and consolidations have become an increasingly common feature of the global higher education landscape. Governments and university leaders pursue mergers for multiple reasons: to create institutions with the critical mass to compete in global rankings, to eliminate duplication and achieve administrative efficiencies, to strengthen research capacity by combining complementary departments, and to address demographic declines in student numbers. Notable recent examples include the creation of Université Paris-Saclay through the merger of multiple French institutions, the consolidation of Chinese universities into larger comprehensive institutions, and ongoing merger discussions in countries such as Australia and the Nordic nations.

From a ranking perspective, mergers often produce a new institution whose rank differs substantially from its predecessor institutions, sometimes in ways that are difficult to predict. Understanding the methodological mechanisms behind these changes is important for interpreting post-merger ranking results and for institutions considering consolidation. The effects are not always positive: some mergers produce anticipated ranking improvements, while others fail to deliver, and understanding why requires examining how each ranking system processes the combined data of merged entities.

How mergers affect ranking indicators

The impact of a merger on rankings depends on the specific indicators each ranking system uses. On research output indicators, a merger typically increases publication and citation counts by combining the outputs of previously separate institutions. In purely size-dependent rankings such as the ARWU and Leiden Ranking, this can produce substantial improvements. However, when rankings normalize by faculty size, the effect depends on whether the merger produces research synergies or simply aggregates existing output. If two institutions with average research productivity merge, their combined output per faculty may remain the same.

Reputation indicators may take years to respond to a merger. Survey respondents may continue to rate the predecessor institutions separately, may be uncertain how to evaluate the new combined entity, or may fail to update their perceptions for some time. This can create a lag between the actual creation of the merged institution and its reflection in reputation scores. Citation metrics also have a temporal dimension: publications authored under predecessor names will continue to accrue citations, and it may take years for the citation profile of the new institution to stabilize. The short-term effect on rankings can therefore be ambiguous, with some indicators rising immediately and others lagging.

Student-staff ratios can be affected in complex ways. If a merger involves combining administrative functions and reducing duplication, the student-staff ratio may improve if redundancies are eliminated. However, if the merger is primarily structural without significant operational changes, student-staff ratios may remain similar to the pre-merger averages. Internationalization indicators can also shift: if one predecessor institution had high international faculty or student ratios and the other did not, the combined ratio may fall between the two. These compositional effects mean that the ranking result of a merger is not simply the sum of its parts.

Strategic considerations and risks

Institutions considering mergers for ranking purposes should carefully model the expected effects across multiple ranking systems. A merger that improves ARWU position through increased publication volume may not help QS rank if the combined institution's reputation scores do not rise commensurately. The costs of merger—financial, organizational, and cultural—must be weighed against realistic projections of ranking improvement. Mergers can also create new challenges, such as the loss of specialist identity, internal cultural conflicts, and the dilution of brand equity if one predecessor institution was more prestigious than the other.

There is evidence that the ranking benefits of mergers are often overstated in the planning phase and that the most dramatic improvements accrue to mergers that combine complementary research strengths, rather than those that simply aggregate underperforming units. A merger of two weak institutions does not necessarily create a strong one. The most successful mergers from a ranking perspective tend to involve at least one institution that already has strong research performance and a clear strategic rationale for combining with a partner that brings specific complementary assets, such as clinical facilities, engineering programs, or specialized research infrastructure.

Post-merger evaluation and data continuity

After a merger, tracking ranking performance requires attention to data continuity. If a ranking organization treats the merged institution as a new entity with a new identifier, historical trend data from the predecessors may be lost, making year-over-year comparison impossible until the new entity accumulates its own track record. Some ranking organizations provide back-calculated scores for merged institutions to maintain continuity, but this requires cooperation and data sharing from the institutions involved. Users should check whether post-merger ranking results are based on a new baseline or on restated historical data.

For ranking users, the key takeaway is that mergers introduce structural breaks in ranking time series. A sudden improvement or decline in a university's rank should be investigated for merger effects before being attributed to genuine performance changes. Always check whether a university has undergone merger, acquisition, or restructuring that could explain its ranking trajectory. Look for institutional announcements and official documentation about the merger, and consider how the specific indicators used by each ranking system might be affected. Rankings are imperfect measures of institutional performance under the best of circumstances, and mergers add an additional layer of complexity that requires careful interpretation.