A Primary Author Citation Index (PACI) or p-index, proposed here, would not count citations of published works by scientists, but would instead determine the proportion (percentage) of all published works [with at least 1 citation] by a scientist for which the scientist is senior (first) author on the publication, regardless of the number of authors on each individual publication (included in the p-index calculation). The intended primary purpose of the p-index is to determine the proportion of a scientist's career publications that the scientist actually contributed to writing the majority portion of the publication (for which the first or primary author is most responsible and credited). The p-index value attempts to quantify a scientist's career accomplishments in terms of completing the entire research cycle, culminating with the actual primary (substantial) writing of all final research and related products (study results and other types of publications). Please do not respond by addressing the many problems associated with undue credit given to scientists in positions of power (over subordinate scientists) or different conventions, policies, or ethics used in determining authorship order (such as which scientists got the grant, did most of the research, or collected most of the data presented in a paper); and please refrain from giving unconstructive opinions.