We have developed an impossibility theorem that shows that it is not possible to link CBA and CEA
if: (i) the axioms of EU theory hold; (ii) the QALY model is valid in a welfare economic sense;
and (iii) illness hinders the ability to enjoy consumption.
Since (iii) is intuitive and (ii) is essential for CEA,
the relaxation of (i) is the only real avenue open for a meaningful welfare economic link between CBA and CEA
(at least where costs are assessed from a societal perspective).