Participation as amicus curiae has long been an important tactic of organized interests in litigation before the U.S. Supreme Court. We analyze amicus curiae briefs filed before the decision on certiorari and assess their impact on the Court's selection of a plenary docket. We hypothesize that one or more briefs advocating or opposing certiorari increase the likelihood of its being granted. We test this hypothesis using data from the United States Reports and Briefs and Records of the United States Supreme Court for the 1982 term. The statistical analysis demonstrates that the presence of amicus curiae briefs filed prior to the decision on certiorari significantly and positively increases the chances of the justices' binding of a case over for full treatment—even after we take into account the full array of variables other scholars have hypothesized or shown to be substantial influences on the decision to grant or deny.
