Ever increasing hardware and software costs are also a serious financial problem. There is a constant need to upgrade and replace equipment if we are to take full advantage of the electronic possibilities, but there is no clear stream of funding for this. Beyond finance however there are serious intellectual or academic concerns which constrain the migration of libraries to a purely electronic environment. Librarians have custodial duty to ensure that the journals can be accessed in the future - the difference now is that the data is not physically present . There is the question of Archiving.
Journals often switch from one publisher to another.
Publishers come and go. The only safe way of archiving an electronic journal is to put it into the public domain. Ownership of text and copyright is a major issue which I have no time to touch on here, except to note that there are moves in America towards Universities putting the research output of their academics on their own web-sites with a view to cutting out the publisher. From the library user perspective the visible results are links from entries in the OPAC catalogue to the electronic versions of individual titles. But Subject Gateway entry and links to journal service providers own sites are via the library Web-site rather than the catalogue.