Jakob Nielsen defines the phaenomenon linkrot, and encourages site owners to fight it by reducing outbound linkrot and securing stability of incoming links.

An overview on results of recent research by Ted Tjaden.

Results of the third State of the Web Survey (SOWS), an automated web survey that tracks page size and linkrot on the WWW.

Wallace Koehler, Valdosta State University, presents the results of his research, and an overview on existing literature. Published in Information Research, Vol. 9 No. 2, January 2004.

An appeal for stability, and advice how to achieve it, by Tim Berners-Lee.

A study by Frank McCown et al., presented at the 5th International Web Archiving Workshop.

Overview article from Wikipedia.