Introduction According to the EU website, ‘equality between women and men is a fundamental right, a common value of the EU, and a necessary condition for the achievement of the EU objectives of growth, employment and social cohesion’. Yet the position of men and women still differs considerably. Women have a lower participation rate, for example, have less political power and are more susceptible to poverty. Given this difference between the stated policy goal and the actual state of affairs, an effective monitoring of gender equality, based on a common set of indicators, seems important. These indicators can reveal strong or weak aspects of a national situation and facilitate inter-country comparisons. The indicators may also be combined in one single figure, a gender equality index. Such an index is very useful to identify relative success in promoting gender equality and to monitor progress over time. Over the last few decades, the relevance and importance of indices in the field of gender equality has been recognised, and several indices have been developed. Measuring gender equality is a rather difficult task, however, as gender equality is a complicated term with diverse dimensions and many layers of meaning. It may refer to a formal equality concept centring on equal starting position (‘level playing field’) or the achievement of equal results. Defining gender equality in terms of equal results seems more ambitious, as the focus shifts from procedures to outcomes, asking not where people start out, but where they end up. At the same time, in as far as outcomes also reflect individual effort or individual choice, the emphasis on equal outcomes raises ethical and policy-relevant issues on individual and societal responsibility (Roemer 2002). More specifically, among feminist authors there has been a strong debate about the one-sidedness of the ‘equality approach’ if this implies women becoming equal to men. For example, it is by no means obvious that women’s position is strengthened by having to work as many hours in paid employment as men. Instead, a difference approach is advocated, which is based on an equal valuation of the different gender roles. The social mandate is therefore not to equalise outcomes, but rather to provide ‘genuine’, unrestricted choice by lifting restrictions (Lewis 2009). Those who advocate egalitarian gender roles, however, may not agree on such a

strategy as a different view seems to rely on essentialist notions of femininity, reinforcing existing stereotypes and the current organisation of gender roles (for an overview of the debate, see Fraser 1997). At a more practical level, the measurement of gender equality in terms of dimensions and indicators may raise several questions. Equality in terms of outcome may, for example, be operationalised in equal labour force participation and equal wages; equality in terms of unrestricted choice may be measured in income equality and equality of respect. In the actual choice of indicators it also has to be taken into account that the indicators must be derived from accessible data sources; especially monitoring progress over time and inter-country comparisons are severely hampered by lack of data. As such, the availability of harmonised databases covering a longer period of time and a large number of countries is an extremely important consideration when constructing an index. Finally, decisions need to be taken on the methodology – that is, the actual calculation of the index. The scores on the dimensions need to be standardised and somehow aggregated. The functional form of the index may differ from a simple linear aggregation formula to a more complicated computation using different weights and different adjustment procedures. Of course, different concepts and different methodologies most likely result in different scores. Yet, the impact on the actual rankings may be rather modest. In this respect, different indices may be interpreted as different perspectives on the same phenomenon: the inequality between men and women. Against this background, the aim of this chapter is to provide an overview of the most important indices, which so far have been developed with regard to gender equality, and to compare these indices in terms of concepts, methodology and outcomes. In particular we will focus on the (implicit) definition of gender equality, the operationalisation in terms of dimensions and indicators, the methodology used and the final scores. Given the scope of the book the emphasis will be on EU countries; also ‘world’ indices will thus only be applied to EU Member States.