This paper applies concentration curves and indices, that have been previously used to analyze progressivity in health care finance and horizontal equity in health care delivery in developed countries, to a 1998-1999 household survey about health care expenditures and utilization carried out in four francophone West African capitals (Abidjan, Bamako, Conakry and Dakar). The paper also uses statistical inference for testing stochastic dominance relationship between curves, a technique already applied in the literature about equity in taxation, as the criterion for making rigorous inequality comparisons. In all four capitals, the results strongly suggest a regressive pattern of payments for health care, with lower income groups bearing an higher burden of health expenditures as a proportion of their income than do the higher income segments of the population. As soon as dominance between concentrations curves is statistically tested, results appear less conclusive, notably for the groups of population affected by severe morbidity, on the issue of horizontal inequity in health care delivery, which requires that persons with similar medical need be treated equally. Some recommendations are made for the use of equity measurements in access to care for future evaluations of the impact of health care reforms in Africa.

This paper enquires into the responsiveness of individuals to information in Contingent Valuation (CV). The impact of information is assessed using a sequential procedure in which individuals are successively presented with different levels of information. Two different types of information have been provided: scientific information about the good and information about the willingness to pay (WTP) values of the other respondents. Responsiveness to information is studied using an innovative CV survey where two groups of over 120 volunteers simultaneously provided their WTP (field experiment) and a standard telephone survey of over 240 respondents. Our results show (1) a higher level of responsiveness to scientific information than to information about the WTP values of other respondents and (2) a higher level of responsiveness in the field experiment than in the telephone survey. We discuss our findings using the theory of commitment borrowed from social psychology and explore the extent to which commitment could be a necessary requirement in the practical application of the CV method.

Contingent valuation (CV) surveys have been criticized for assuming that respondents have well-defined preferences. Using an innovative field experiment dealing with a privatized public good, it is shown that respondents are not influenced by public opinion but are positively responsive to scientific information.

Despite the acceptance that health gain is the most important attribute of health care, other aspects of health care may affect utility. The aim of this paper is to report an experiment to test the impact of providing different levels of information in the context of the EuroWill study, a joint contingent valuation (CV) of multiple health programmes. Three hundred and three respondents were simultaneously asked for their willingness-to-pay (WTP) for three health care programmes: more heart operations, a new breast cancer treatment and a helicopter ambulance service. To test for the impact of variation in information, three versions of one of the programmes (heart) were provided. Results show that WTP for all three programmes tended to be significantly higher for respondents who were provided additional positive information about the heart programme. Our results show that CV of health care programmes, which only take into account medical outcomes, may lead to the value of such programmes not being adequately estimated, and that the impact of information may even be more decisive in the context of joint evaluation of multiple, rather than single, programmes.