Objective interpersonal comparisons of utility

This paper examines the problem of distilling conflicting interpersonal comparisons into a single set of interpersonal comparisons. The mapping that achieves this has a richer co-domain than all social choice problems (and a richer domain than most social choice problems). The set of mappings satisfying a mild set of restrictions is very small. If interpersonal comparisons embody ratio-scale comparability then the mapping is Cobb-Douglas in form; if interpersonal comparisons embody no more than level and difference comparability then the mapping must be dictatorial and it is impossible to combine different interpersonal comparisons.