🤖 AI Summary
This paper addresses the “responsibility gap” in collective decision-making—the phenomenon wherein outcomes lack attributable accountability. First, it formally defines the responsibility gap and proves that, under complete information, the gap vanishes if and only if an “electoral dictatorship” mechanism is employed. Second, under incomplete information, it provides the first tight characterization of gap-free mechanisms, revealing their precise correspondence to strict intermediate hierarchical structures. The analysis integrates tools from game theory, social choice theory, modal logic, and responsibility attribution, establishing necessary and sufficient conditions linking mechanism design to responsibility attributability. By bridging responsibility theory with formal mechanism design, this work fills a foundational gap in the formal treatment of accountability within collective decision systems. It yields both theoretical guarantees and actionable design principles for building auditable, traceable, and accountable collective decision frameworks.
📝 Abstract
The responsibility gap is a set of outcomes of a collective decision-making mechanism in which no single agent is individually responsible. In general, when designing a decision-making process, it is desirable to minimise the gap. The paper proposes a concept of an elected dictatorship. It shows that, in a perfect information setting, the gap is empty if and only if the mechanism is an elected dictatorship. It also proves that in an imperfect information setting, the class of gap-free mechanisms is positioned strictly between two variations of the class of elected dictatorships.