This Article discusses issues with how the success of aggregate agency rulemaking is evaluated. Rigorous methods are used for assessing the ‘optimality’—according to a chosen criterion—of individual agency regulations, and procedures such as Cost-Benefit Analysis provide a way for agencies to estimate how effective a considered regulation will be. By contrast, overall agency behavior (over the course of a period of time or of a regulatory program) is not evaluated nearly as stringently, leading to politicized debates and band-aid solutions. To help bring the rigor used in individual rulemaking to the evaluation of aggregate agency behavior, this Article proposes a definition of “broad optimality” and presents a comprehensive taxonomy of the ways in which an agency may fail to achieve it. This Article also discusses why agencies fall short of achieving broad optimality and implications for agency procedure