Impact of foreign external PhD examiners on academic collaboration patterns

The external examiners of 166 Swedish and 168 Danish biomedical PhD-theses, the candidates and their supervisors were assessed bibliometrically. In Sweden, 43 % of examiners were from abroad, most commonly USA and UK, while in Denmark 39 % of theses were examined by an examiner from abroad, mostly from neighbouring Sweden. As many came from Canada as from Denmark to examine Swedish theses. Foreign examiners were more merited (based on number of publications) than domestic examiners. Foreign examiners examined significantly more men in Denmark and more women in Sweden. In the case of co-publication only after the examination, one Swedish and three Danish PhD-candidates published with their foreign external examiners 4–10 years after the examination and two Swedish and seven Danish supervisors co-published with foreign examiners, suggesting that although invitation of foreign external examiners only rarely lead to collaborative work it may be more common in Denmark than in Sweden. Co-publication between external examiners and the candidates or their supervisors was rarer in Sweden than in Denmark in the period surrounding the examination, although the numbers are small. The use of foreign external examiners stimulates academic intercourse in general and sets a useful benchmark for common PhD standards but does not markedly increase international collaboration after the examination.