Mobile researchers have higher productivity – Study

A study of researcher mobility at 28 Swedish higher education institutions provides new and detailed data on how researchers move between institutions, nationally and internationally and confirms the positive impact of mobility on publication quality.

The results indicate that mobile researchers get higher citation rates and they are also more productive than the average.

Among the mobility categories, the so-called sedentary researchers, or researchers who have only published at one higher education institution, get the lowest values for productivity and publication quality (field-weighted citation impact). However, they are also the youngest.

At the other end of the scale, transitory researchers who have had one or several shorter periods at different higher education institutions are the most productive and have the highest publication quality.

Another result is that the large higher education institutions typically have more international mobility than the small ones.

The study, Researchers’ Mobility in Swedish Higher Education Institutions, was produced for STINT – the Swedish Foundation for International Cooperation in Research and Higher Education – by Steven Scheerooren of Elsevier’s Analytical Services and was presented at a conference in Stockholm on 9 December.

Internationalisation index

The study is a follow-up of the STINT Internationalisation Index, whose findings were reported by University World News in September.

The report on researcher mobility maps out how researchers move between higher education institutions and in particular if a researcher has academic experience from abroad.

The STINT Internationalisation Index already captures a combined index of institutional international experience of scientific staff correlated to productivity by finding their share of international co-authored international publications in the Elsevier Scopus database; share of students in and out or to and from abroad; share of international PhD students; share of credits given in other languages than Swedish; share of staff with completed PhD degrees and-or who have done research at a foreign institution, and by sending a questionnaire to the institutional top leadership on their international experience.

Based on this index STINT wanted to expand its knowledge about the consequences of mobility on research performance and develop a more robust methodology for mobility studies.

The project selected 28 Swedish higher education institutions and mapped out their affiliations in publication data to reflect mobility of individual researchers with Scopus publications, considering all Swedish affiliations with at least one institution found in the Scopus database for the period 1996 to 2015.

Illustrative charts

The report uses illustrative charts for the 28 higher education institutions selected in a ‘brain circulation map’ for three types of mobility: national, international and overall.

The maps are based on all still-active researchers who have published at least once with affiliation to one of the 28 higher education institutions during 1996 to 2015.

Central to this methodology, adapted from international science and technology indicator research and presented in detail in an appendix, is how citations that are attributed to one institution compare with a world average, which in the report is calculated as a Field-Weighted Citation Impact, or FWCI, index.

This index varies from 1.00 indicating a citation frequency equal to world average to a positive index indicating a percentage point share above the world average. For example, an FWCI of 2.11 is indicating a 111% greater citation frequency than the world average, while a lower FWCI than 1, for instance 0.87, is indicating a 13% lower citation frequency.

The Scopus Elsevier database of peer-reviewed publications covers 62 million documents in over 22,500 publications by more than 6,000 publishers. Reference lists are captured for 39 million records published from 1996, for the first years mostly from journal articles but from 2013 also including books.

The publication output for the 28 Swedish higher education-affiliated scientists for the period 2011-15 totals 176,349 publications. All 28 institutions have an FWCI higher than the world average, the highest being at the Stockholm School of Economics with 2.18 and the Karolinska Institute with an FWCI of 2.09.

To measure researcher mobility the study looks at four main categories: Sedentary researchers who do not appear to have left their current affiliation, inflow researchers coming to a Swedish higher education institution; outflow researchers leaving the institution, and transitory researchers who stay at the institution or elsewhere for less than two years.

The study found that sedentary researchers have typically the lowest FWCI and are scoring below average both in relative productivity and in relative age.

At the other end of the scale are the transitory researchers who have had one or several shorter periods at different higher education institutions. They are the most productive and have the highest publication quality.

One conclusion at the seminar was that there is a great need for improved data and methods to capture the effects of mobilisation on scientific productivity.

Similar Danish study

Jeppe Wohlert, senior advisor at DEA in Copenhagen, Denmark, who is presently principal investigator for a similar researcher mobility and productivity project in Denmark, told University World News: “The STINT-Elsevier report is very interesting and we strongly support any study that can bring more knowledge about the impact of researchers’ mobility on their productivity."

However, he said his research shows that productivity goes up and down according to whether a researcher moves to a higher-ranked or lower-ranked university.

“In the research we have come across, there is no evidence that mobility automatically increases the scientific productivity of researchers.

“For example, research shows that mobility to a lower-ranked university is followed by a decrease in the number of publications, while going on a research stay or taking up a position at a higher-ranked university is associated with a positive increase in productivity but no quality effect,” he said.

He said in both cases their research finds strong evidence of short-term negative effects, which could be due to issues of adapting to a new work culture in a different research environment and country, or practical problems such as having to learn about tax and immigration rules and find housing, which can take incoming researchers months to deal with before being able to focus fully on their research.

“This is not fully in line with the result of the STINT study, which indicates that mobile researchers are more productive and receive higher citation impacts. More mobility research is obviously needed,” Wohlert said.