Fang-Yi Chiou, Research Fellow at the Institute of Political Science, Academia Sinica, collaborated with Professor Jonathan Klingler, Assistant Professor at the University of Mississippi, to investigate the rulemaking process in the United States. The study aims to determine whether the president or Congress holds greater influence over the rules established under the separation of powers and examines the factors influencing this dynamic. Employing a web crawling automation technique, the paper generates a comprehensive dataset of rules and utilizes a novel item response model for significance measurement. Additionally, three competing game-theoretic models are proposed. The research applies this new measurement to analyze how the president and Congress compete to shape the rulemaking productivity of different departments. It uncovers that the relative influence of the president and Congress varies based on the significance of the rules. Published in the November 2023 issue of the American Political Science Review, a top-ranked journal in political science, this paper provides valuable insights into the dynamics of rulemaking in the U.S.