Research Assessment, Research Funding, and Citation Impact
“Correlation between RAE ratings and mean departmental citations +0.91 (1996) +0.86 (2001) (Psychology)”

RAE and citation counting measure broadly the same thing

“Citation counting is both more cost-effective and more transparent”

                     (Eysenck & Smith 2002)                     

http://psyserver.pc.rhbnc.ac.uk/citations.pdf