Aggregation of incomplete ordinal preferences with approximate interpersonal comparisons

We develop a model of preference aggregation where people's psychological characteristics are mutable (hence, potential objects of individual or social choice), their preferences may be incomplete, and approximate interpersonal comparisons of well-being are possible. Formally, we consider preference aggregation when individual preferences are described by an incomplete, yet interpersonally comparable, preference order on a space of psychophysical states. Within this framework we characterize three preference aggregators: the `Suppes-Sen' preorder, the `approximate maximin' preorder, and the `approximate leximin' preorder.