Governance structures for new technologies are frequently top-down, reactive, and informally enforced, leaving marginalized communities with little power to address harms until after they occur. To address these limitations, we introduce Proactive Accountability, a conceptual framework theorizing that effective governance must be community-led, formally enforced, and continually maintained. We explore these principles through a speculative design study with Detroit's food sovereignty community, in which participants identified community-owned cooperatives---described as ``ancestral technologies''---as a model for redistributing power within a capitalist economy. Synthesizing these theoretical and empirical insights, we introduce the Designing for Proactive Accountability (D4PA) framework, providing implications for how designers can operationalize the goals of proactive accountability into HCI research and design projects. Finally, we contribute a future research agenda that positions cooperatives not merely as beneficiaries of design, but as sites of inquiry for understanding how to institutionalize justice-oriented democratic governance of sociotechnical systems.
ACM CHI Conference on Human Factors in Computing Systems