BackgroundThis paper examines an aspect of the problem of measuring inequality in health services. The measures that are commonly applied can be misleading because such measures obscure the difficulty in obtaining a complete ranking of distributions. The nature of the social welfare function underlying these measures is important. The overall object is to demonstrate that varying implications for the welfare of society result from inequality measures.MethodVarious tools for measuring a distribution are applied to some illustrative data on four distributions about mental health services. Although these data refer to this one aspect of health, the exercise is of broader relevance than mental health. The summary measures of dispersion conventionally used in empirical work are applied to the data here, such as the standard deviation, the coefficient of variation, the relative mean deviation and the Gini coefficient. Other, less commonly used measures also are applied, such as Theil's Index of Entropy, Atkinson's Measure (using two differing assumptions about the inequality aversion parameter). Lorenz curves are also drawn for these distributions.ResultsDistributions are shown to have differing rankings (in terms of which is more equal than another), depending on which measure is applied.ConclusionThe scope and content of the literature from the past decade about health inequalities and inequities suggest that the economic literature from the past 100 years about inequality and inequity may have been overlooked, generally speaking, in the health inequalities and inequity literature. An understanding of economic theory and economic method, partly introduced in this article, is helpful in analysing health inequality and inequity.

This paper provides a background to the mental health policy changes introduced by the Council of Australian Governments (COAG) in 2006. It then considers a major Australian Government COAG reform, the revision of the Medicare Benefits Schedule (MBS), by analysing the month-by-month utilisation of the available time-series data for the 17-month period (1 November 2006-31 March 2008) when new items for psychologists, social workers and occupational therapists were introduced. There are a number of unique problems associated with monthly time-series data. Essentially, there is a problem of heterogeneity that arises from the non-uniformity of the temporal unit of a 'month'. Second, there is an issue of the population covered by Medicare altering through time. Both of these problems are addressed in the present analysis of the time-series data. The two groups of psychologists created by the MBS changes dominate the provision of the new services, providing 96.4% of the new services. Psychologists, who are not deemed clinical psychologists in the MBS changes, are the group providing most of the services. Virtually all services are individual, not group, and are provided in a consulting room. The temporal adoption of the new items was continuing to grow by March 2008. Implications of this analysis for psychologists are discussed.