The purpose of this research is to investigate: how many journal titles are both in LOCKSS and in Portico?; what is the relationship of small publishers to LOCKSS/CLOCKSS and Portico?; and what is the relationship of large publishers to LOCKSS/CLOCKSS and Portico?
The paper describes how data from Portico, LOCKSS, and CLOCKSS were cleaned and analyzed using Perl programs to discover duplications.
The findings show a significant overlap among the archiving systems. They also show that Portico has no prejudice against small publishers and that large publishers are as willing to choose the LOCKSS software as to choose Portico. LOCKSS does, however, archive many more small and arguably endangered publishers and may be the only economically viable choice for them.
The push for greater transparency has made more and more data available. Both LOCKSS and Portico deserve commendation for providing the detailed lists of titles and publishers on which this paper was based. Such data give the library community an opportunity to build decisions about the long‐term digital future on firm and verifiable ground.
