January 25, 2022

New Working Paper: “Perma: Scoping and Addressing the Problem of Link and Reference Rot in Legal Citations” & Introducing Perma.cc

A new working paper by Zittrain, Albert, and Lessig, at Harvard.

Make sure to note a new service (launching soon) named Perma.cc that’s being developed by Harvard Library Innovation Lab. It is possible to request beta access.

Working Paper


Perma: Scoping and Addressing the Problem of Link and Reference Rot in Legal Citations


Jonathan Zittrain
Harvard Law School and Kennedy School;
Harvard School of Engineering and Applied Sciences
Berkman Center for Internet & Society

Kendra Albert
Harvard Law School 

Lawrence Lessig
Harvard University – Edmond J. Safra Center for Ethics
Harvard Law School 


via SSRN


We document a serious problem of reference rot: more than 70% of the URLs within the Harvard Law Review and other journals, and 50% of the URLs found within U.S. Supreme Court opinions do not link to the originally cited information.

Given that, we propose a solution for authors and editors of new scholarship that involves libraries undertaking the distributed, long-term preservation of link contents.

Direct to Full Text Article (16 pages; PDF)


From a Blog Post About the Research Paper by Jonathan Zittrain:

Harvard Library Innovation Lab has pioneered a project to unite libraries so that link rot can be mitigated.  We are joined by about thirty law libraries around the world to start Perma.cc, which will allow those libraries on direction of authors and journal editors to store permanent caches of otherwise ephemeral links.  Libraries are the ideal partners for this task: they think on a long timescale; they take user trust and service seriously; and they are non-commercial. You can see more about the system at perma.cc.  The amazing Internet Archive has lent its archiving engine to the effort, and Instapaper has generously provided an alternative path to parse Web pages to be saved.  CloudFlare has kindly ensured that the the system at Perma.cc can scale with use.

Related Work

Something Rotten in the State of Legal Citation: The Life Span of a United States Supreme Court Citation Containing an Internet Link (1996-2010)
by Raizel Liebler and June Liebart
15 Yale Journal of Law & Technology, Spring 2013


Other infoDOCKET Posts About Link Rot

See Also:  Link Rot: Georgetown Law Library Finds 38 Percent of Online Documents Disappear from Web Pages Within Five Years (March 3, 2012)

See Also: 2011 Report on Link Rot” (March 3, 2011)
Research from Chesapeake Project Legal Information Archive.

About Gary Price

Gary Price (gprice@mediasourceinc.com) is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at Ask.com, and is currently a contributing editor at Search Engine Land.