Including informal care in economic evaluations is increasingly advocated but problematic. We investigated three well-known concerns regarding contingent valuation (CV): (1) the item non-response of CV values, (2) the sensitivity of CV values to the individual circumstances of caring, and (3) the choice of valuation method by comparing willingness-to-pay (WTP) and willingness-to-accept (WTA) values for a hypothetical marginal change in hours of informal care currently provided.