Most studies of policy change within the ACF have been descriptive, single-instance explorations that confirm one or more of its four pathways: external shocks, internal shocks, negotiated agreements, and policy-oriented learning. To advance ACF studies of policy change, this chapter takes a different approach to assessing the drivers of change. Rather than looking to confirm one of the four pathways for a single instance of change, we inductively explore what policy actors cite as “antecedents”—or potential influencing, motivating, or driving factors—for multiple policy changes in a textbook subsystem. We identify antecedents through policy actor references in the public discourse related to 77 new or modified policies in the Colorado oil and gas subsystem between 2007 and 2021, drawing on public and government documents, public testimony, and news articles. We then compare the inductively identified antecedents of each policy change with the four pathways of change outlined within the ACF. We find references to internal antecedents were the most commonly mentioned, followed by references to external antecedents. We conclude by discussing the significance of these results for studying policy change, the importance of including both inductive and deductive methods to expand the existing pathways, and guidelines for conducting a medium-sized analysis of policy change over time.