Journal of Economic Behavior & Organization Vol. 48 (2002) 1–14 Are preferences stable? The case of health care Fernando San Miguel ∗ , Mandy Ryan, Anthony Scott Health Economics Research Unit, Department of Public Health, University of Aberdeen, Medical buildings, Foresterhill, Aberdeen, Scotland AB25 9ZD, UK Received 19 June 2001; accepted 22 August 2001 Abstract Experiments concerned with modelling individual preferences are based on the assumption of stability of preferences. Violations of the stability assumption have implications for the increasing amount of experimental work in health care concerned with the welfare implications of alternative policies. This paper reports the results of a discrete choice experiment (DCE) carried out to examine the effect of experience on stability of preferences within health care. Whilst the results provide evidence of stability, further research is required before these results are generalised. © 2002 Elsevier Science B.V. All rights reserved. JEL classification: C9; I1 Keywords: Stability; Discrete choice experiments; Health care 1. Introduction Preferences are assumed to be stable in economic equilibrium analysis, that is, an indi- vidual facing the same choice at different points in time will express the same preference (Friedman, 1962; Becker, 1976; Stigler and Becker, 1977). This assumption is tested here using a discrete choice experiment (DCE) that elicits preferences for out-of-hours care by general practitioners. Given the lack of revealed preference data in publicly provided health care systems, ex- perimental techniques have been used to estimate the welfare implications of alternative government policies. Such techniques include standard gamble and time trade-off (Torrance et al., 1982; Dolan et al., 1996), willingness to pay (WTP) (Diener et al., 1998) and DCE (Ryan, 1999). Implicit in the application of all these experimental techniques is the as- sumption of stability of preferences. However, given the nature of the commodity health ∗ Corresponding author. Tel.: +44-1224-552764; fax: +44-1224-662994. E-mail address: sm.fernando@abdn.ac.uk (F. San Miguel). 0167-2681/02/$ – see front matter © 2002 Elsevier Science B.V. All rights reserved. PII:S0167-2681(01)00220-7