Citations referenced but not read

Ram Narayanan recently forwarded me a copy of an interesting article on citing papers without reading them (thanks, Ram!). The authors of this paper developed formulas for estimating the percentage of people who cite a paper without actually reading that paper. They claim that if one paper has an error in a citation (e.g., the wrong page number) then people who copy that citation without reading the original paper will pass on that error. Their formula relating the number of authors who read a citation to the number of authors who cite that paper is given by