Before revision:  Because perceptions of quality are a key factor in citing decisions, citation counts are likely to endogenously cause more citing of top papers and equating them with quality overestimates the actual quality of those papers. Conversely, 54\% of references had either zero or minor influence on authors who cite them, but references to highly citedpapers were about 200\% more likely to denote substantial impact. Equating citations with impact thus underestimates the impact of highly cited papers . Real citation practices thus reveal that citations are biased measures of quality and impact .
After revision:  Because perceptions of quality . Accounting for citation types thus reveals a "double status effect": in addition to affecting how often a work is cited, status affects how meaningfully it is cited. Consequently, highly cited papers . Real citation practices thus reveal that citations are biased measures of quality and impact .