Article summary
Extends classical ideal point estimation to allow voters to express different preferences across distinct policy domains (for example, agriculture versus defense). The scaling procedure recovers estimated ideal points on a common scale so revealed preferences can be compared directly across domains. That comparison makes it possible to assess whether a member votes more conservatively in one domain than another and to evaluate the extent to which an individual’s voting behavior conforms to a uni-dimensional spatial model (i.e., whether preferences are constant across domains).