Age limits unproven

You report on the abstract of a Canadian study (“How to boost scientific production? A statistical analysis of research funding and other influencing factors”, published in Scientometrics) that purports to show that scientific productivity declines as scientists get older. I suggest that you read the rather flawed paper, as no such conclusion follows from the data, and the article actually states, “In general, older researchers can be more productive.”

Because the study uses only Natural Sciences and Engineering Research Council of Canada funding, it is irretrievably biased (in the statistical sense). Oddly, it presents this as a virtue: “the common procedure in the similar studies is extracting the funded researchers’ data and then gathering all the articles that were published by those researchers. This must have resulted in an over-estimation of the number of articles, as researchers usually use several sources of funding.” Obviously older people may simply have a different proportion of “other funding”. The “career age” (date since first publication) extends only to 15 years, which means only to researchers in their forties, but “it seems that as the career age of the researcher grows, his/her productivity also increases and peaks at a certain age”. The largest correlation coefficient is just 0.37, and that is between the number of articles in adjacent years by individuals. The p‑values are high simply because of the large number of observations (84,048). Overall, the data do not allow one to draw any worthwhile conclusions on any relationship between career age and scientific productivity.

Douglas Kell, aged 62 and ¾
Research chair in bioanalytical science
University of Manchester

Send to

Letters should be sent to: THE.Letters@tesglobal.com
Letters for publication in Times Higher Education should arrive by 9am Monday.
View terms and conditions.