Diffusion of Responsibility in Collective Decision Making

TL;DR

This paper analyzes how responsibility diffuses in collective decision-making, showing that to prevent diffusion, mechanisms must be dictatorial or elected dictatorial, especially as the number of agents increases.

Contribution

It introduces a formal framework for understanding responsibility diffusion and characterizes mechanisms that avoid it as dictatorships or elected dictatorships.

Findings

For two agents, only unilateral decision-making prevents diffusion.

With more than two agents, only elected dictatorships prevent diffusion.

Bisimulation preserves responsibility properties in decision mechanisms.

Abstract

The term "diffusion of responsibility'' refers to situations in which multiple agents share responsibility for an outcome, obscuring individual accountability. This paper examines this frequently undesirable phenomenon in the context of collective decision-making mechanisms. The work shows that if a decision is made by two agents, then the only way to avoid diffusion of responsibility is for one agent to act as a "dictator'', making the decision unilaterally. In scenarios with more than two agents, any diffusion-free mechanism is an "elected dictatorship'' where the agents elect a single agent to make a unilateral decision. The technical results are obtained by defining a bisimulation of decision-making mechanisms, proving that bisimulation preserves responsibility-related properties, and establishing the results for a smallest bisimular mechanism.