What counts? Policy evidence in public hearing testimonies: the case of single-payer healthcare in New York State

While few would advocate that policy decisions be based solely on interest group influence or political pandering, few would also agree that decisions be based solely on evidence from randomized trials devoid of context or attention to stakeholder concerns. Yet, this is the implicit tension that has emerged between scholars, who privilege rigorously established research evidence as the primary legitimate basis for policy decision-making, and their critics, who advocate for a broader evidence boundary. However, the policy literature has hitherto failed to suggest an appropriate means of processing various forms of evidence to inform the policy decision-making process. This challenge is especially apparent in public hearings, a frequently used participatory medium where a great variety of evidence is presented. In this paper, we aim to reevaluate the value of public hearings as a means of collecting evidence by exploring 189 testimonies across six public hearings on single-payer healthcare in New York State. At the same time, we evaluate and categorize the types of evidence invoked in public hearings and compare this against what might “count” as evidence from an EBP perspective. Results highlight nine types of “evidence”, along two dimensions: observation span and form of knowledge. We find that applying a narrow boundary of research evidence, only one of nine types of evidence fit that classification: problem-based research. We conclude by suggesting that policy scholars expand their consideration of what types of evidence claims are useful to policymakers.