Congressional enactments and executive orders instruct agencies to publish their anticipated rules in what is known as the Unified Agenda. The Agenda’s stated purpose is to ensure that political actors can monitor regulatory development. Agencies have come under fire in recent years, however, for conspicuous omissions and irregularities. Critics allege that agencies hide their regulations from the public strategically, that is, to thwart potential political opposition. Others contend that such behavior is benign, perhaps the inevitable result of changing internal priorities or unforeseen events. To examine these competing hypotheses, this Article uses a new dataset spanning over thirty years of rulemaking (1983–2014). Uniquely, the dataset ...