Accounting for Framing-Effects - an informational approach to intensionality in the Bolker-Jeffrey decision model

We suscribe to an account of framing-effects in decision theory in terms of an inference to a background informationa by the hearer when a speaker uses a certain frame while other equivalent frames were also available. This account was sketched by Craig McKenzie. We embed it in Bolker-Jeffrey decision model (or logic of action) - one main reason of this is that this latter model makes preferences bear on propositions. We can deduce a given anomaly or cognitive bias (namely framing-effects) in a formal decision theory. This leads to some philosophical considerations on the relationship between the rationality of preferences and the sensitivity to descriptions or labels of states of affairs (intensionality) in decision-making.