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Thursday, April 22, 2010

Do Pressures to Publish Increase Scientists’ Bias?

The objectivity and integrity of contemporary science faces many threats. A cause of particular concern is the growing competition for research funding and academic positions, which, combined with an increasing use of bibliometric parameters to evaluate careers (e.g. number of publications and the impact factor of the journals they appeared in), pressures scientists into continuously producing ‘‘publishable’’ results.

Quantitative studies have repeatedly shown that financial interests can influence the outcome of biomedical research but they appear to have neglected the much more widespread conflict of interest created by scientists’ need to publish. Yet, fears that the professionalization of research might compromise its objectivity and integrity had been expressed already in the 19th century. Since then, the competitiveness and precariousness of scientific careers have increased, and evidence that this might encourage misconduct has accumulated. Scientists in focus groups suggested that the need to compete in academia is a threat to scientific integrity, and those guilty of scientific misconduct often invoke excessive pressures to produce as a partial justification for their actions. Surveys suggest that competitive research environments decrease the likelihood to follow scientific ideals and increase the likelihood to witness scientific misconduct. However, no direct, quantitative study has verified the connection between pressures to publish and bias in the scientific literature, so the existence and gravity of the problem are still a matter of speculation and debate.

To verify this hypothesis, this study analysed a random sample of papers published between 2000 and 2007 that had a corresponding author based in the US. These papers, published in all disciplines, declared to have tested a hypothesis, and it was determined whether they concluded to have found a ‘‘positive’’ (full or partial) or a ‘‘negative’’ support for the tested hypothesis. Using data compiled by the National Science Foundation, the proportion of ‘‘positive’’ results was then regressed against a sheer measure of academic productivity: the number of articles published per-capita (i.e. per doctorate holder in academia) in each US state, controlling for the effects of per-capita research expenditure. Therefore, if publication pressures increase scientific bias, the frequency of ‘‘positive’’ results in the literature should be higher in the more competitive and ‘‘productive’’ academic environments. This study verified this hypothesis by measuring the frequency of positive results in a large random sample of papers with a corresponding author based in the US.

Across all disciplines, papers were more likely to support a tested hypothesis if their corresponding authors were working in states that, according to NSF data, produced more academic papers per capita. The size of this effect increased when controlling for state’s per capita R&D expenditure and for study characteristics that previous research showed to correlate with the frequency of positive results, including discipline and methodology. Although the confounding effect of institutions’ prestige could not be excluded (researchers in the more productive universities could be the most clever and successful in their experiments), these results support the hypothesis that competitive academic environments increase not only scientists’ productivity but also their bias. The same phenomenon might be observed in other countries where academic competition and pressures to publish are high.

Do Pressures to Publish Increase Scientists’ Bias? An Empirical Support from US States Data. 2010 PLoS ONE 5(4): e10271. doi:10.1371/journal.pone.0010271