Abstract: This paper argues that the discretion-constraining impulses of most regulatory reinvention efforts fail to respond to the most serious weaknesses of rulemaking, implementation and enforcement. This is partly because reformers are encumbered by the theory and practice of interest representation and partly because administrative law lacks an alternative model of administrative decision making. The paper's purposes are threefold: (1) to offer a normative vision of collaborative governance against which to evaluate proposals for reform. Collaboration requires problem-solving, provisional solutions, broad participation, public-private sharing of responsibility and a flexible, engaged agency. (2) to illustrate how some innovative administrative processes, such as regulatory negotiation and negotiated permitting, embody elements of the collaborative model and to explain why, despite their promise, they fall short of the collaborative ideal. As examples, the paper relies on four case studies, two each of regulatory negotiation and EPA's Project XL. (3) to argue that the pursuit of collaboration requires a willingness to experiment with non-traditional source of accountability in order to address the problem of legitimacy.