The results below are oldish, but interesting around the rate of retractions in the scholarly literature, and there is currently a bit of a debate going on around retractions (e.g. What a massive database of retracted papers reveals about science publishing’s ‘death penalty’ | Science | AAAS
Steen RG, Casadevall A, Fang FC (2013) Why Has the Number of Scientific Retractions Increased? PLoS ONE 8(7): e68397. doi:10.1371/journal.pone.0068397 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0068397
The increase in retracted articles appears to reflect changes in the behaviour of both authors and institutions. Lower barriers to publication of flawed articles are seen in the increase in number and proportion of retractions by authors with a single retraction. Lower barriers to retraction are apparent in an increase in retraction for “new” offenses such as plagiarism and a decrease in the time-to-retraction of flawed work.
In “Misconduct accounts for the majority of retracted scientific publications”
Proc Natl Acad Sci U S A. 2012 Oct 16; 109(42): 17028–17033. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3479492/
Journal-impact factor showed a highly significant correlation with retractions because of fraud or error but not with those because of plagiarism or duplicate publication ( Fig. 3 A–C ). Moreover, the mean impact factors of journals retracting articles because of fraud or error differed significantly from that of journals retracting articles because of plagiarism or duplicate publication. Accordingly, retractions for fraud or error and retractions for plagiarism or duplicate publication were encountered in distinct subsets of journals, with differences in impact factor ( Fig. 3D ) and limited overlap ( Table 1 ).
Reading these it kind of seems that increase in rates of retractions may be related to both changes in behaviour and changes in norms, which makes a straight up companion of retractions “then” and “now” a slightly subtle exercise.