The extensive literature about the George W. Bush administration's Program Assessment Rating Tool (PART) has not emphasized an issue that appears quite clearly in interviews with senior Office of Management and Budget (OMB) and congressional staff. Budget analysis can pursue efficiency in two ways. One, the object of traditional analysis, involves assessing programs to understand the ratio of inputs to outputs within an agency, and thus the effects of more or less funding. Another approach, termed “budgeting for results,” measures program performance so as to allocate funding among programs in a way that increases total welfare. The second approach is much more difficult because it necessitates comparison of measures of unlike phenomena, requires expertise that often does not exist, and is more easily contested as invoking values rather than facts. Both congressional and OMB sources report concerns that PART weakened budget analysis by diverting resources from traditional analysis. If one goal of reformers is for the OMB to provide analysis that will influence Congress, the focus should be on strengthening the capacity to do traditional budget analysis.