Endogeny in measuring research excellence. In-house publishing and conflict of interests in Polish science evaluation

The ministerial exercise of evaluation of scientific institutions gained a pivotal role in the Polish system of science and higher education after the 2018 reform. The evaluation process under the new rules was concluded in 2022, and in the fields of social sciences and humanities (SSH), it was based to a large extent on domestic publications. We have compiled a sample of articles in journals that exerted the highest impact in the four selected SSH disciplines (over 19 thousand articles in 67 journals) to show elements of partiality in how the evaluation was administered. In particular, we show that a degree of control over a journal prompted a substantially higher share of in-house (endogenous) publications, and we point to clear signs of adaptation by editors to the changes in evaluation rules introduced by the Ministry of Science. The results of that particular national case illustrate that domestic indicators of research excellence are relatively prone to bias, as institutions very often have dual and conflicting roles. • Ministerial research evaluation plays a pivotal role in Polish scientific system. • Evaluation incentivizes adaptation strategies in both researchers and publishers. • Arbitrary changes to ministerial registry played a key role in publishing patterns. • High rank given to domestic journal invited increase in in-house publications. • Degree of control over a journal highly correlated with publishing endogeny.