Proxy Failure
When a measure becomes a target, it ceases to be a good measure. This phenomenon has received numerous names and has been observed across a broad range of contexts, ranging from macroeconomics to machine-learning to ecology. Is this similarity superficial, or does it imply a unified underlying mechanism? We argue that there are real structural similarities that lead to this phenomenon, which we label “proxy failure”. Our account provides a novel perspective on the organization and dynamics of goal-oriented behaviour across biological and social scales.