Representations of preferences with pseudolinear utility functions

We provide an axiomatization of preferences that are representable by pseudolinear utility functions on product spaces C × R . A set of necessary and sufficient axioms that a binary relation must fulfill to be representable by a pseudolinear utility function is given. Our framework gives axiomatic foundations to the “money in the utility function” approach in monetary economics. Axiomatizations of quasilinear utility functions, of separable pseudolinear utility functions, of group separable pseudolinear utility functions are derived. A particular attention is given to additive separable pseudolinear utility functions. Extensions to C × I with I a non-degenerate open interval of R are given. An axiomatization of Cobb–Douglas utility functions is obtained.