The broad scope of the Sustainable Development Goals acknowledges that human development is multifaceted and that gender equality is crosscutting.
In the drive to measure these concepts and gauge progress, there has been a proliferation of indices in recent years. The allure of indices is twofold: they reduce complex concepts and multiple indicators into one number, and this number can be used to rank countries and, so the theory goes, drive change. In one fell swoop then, indices seem to bring simplicity, order, and transformative potential.
But for issues like women’s empowerment and gender equality, does the ever-increasing number of indices produce new, actionable insights? Only indices that have a solid analytical grounding, are built on good data, and convey a clear policy message may help move the needle on gender equality.
The six rules of good indices
Indices synthesize values from discrete indicators into a single measure. There are six basic rules that good indices should follow:
A solid conceptual framework is necessary to build a meaningful index. For example, the Gender Inequality Index (GII) is based on Sen’s framework of capabilities and opportunities.
Simplicity of design and ease of interpretation are crucial to avoid misuse.
A clear purpose is necessary, particularly if the index is intended for policy decisions in addition to a communications function—its results should trigger clear policy responses.
Data availability is key, as without data there is no index.
A sound methodology, to convert indicators with different properties into a single composite measure, and sound judgment in assigning weights to these indicators, are essential.
And last, new indices should offer new insights, not duplicate rankings.
Good indices depend on more and better gender data
Two particular limitations to indices cause concern in the statistical community (and have prompted a coalition of UN agencies and the University of Geneva to launch a Coursera course on the topic):
First, indices are only as good as the data they are built with. This raises particular concerns for gender equality indices because, given the lack of and poor quality gender data available, they will struggle to accurately reflect reality for women and girls. This lack of data is clearly articulated in the new World Bank Human Capital Index (HCI). The data shortcomings are noted by Kraay, in the hope that they will galvanize action: child and adult survival rates are imprecisely estimated in countries where vital registries are incomplete; data on enrollment rates have gaps; reliable measures of quality schooling don’t exist; and test scores are not representative of all students.
Second, indices are aggregations that can hide realities for particular groups, resulting in comparability between countries, but little helpful information for policymakers on which groups to target for intervention. For groups of girls who suffer from intersecting disadvantage, such as girls from indigenous and afrodescendent groups in Latin America, averages may conceal that they trail both boys and other girls in their cohort. For them, overreliance on indices exacerbates their chances of being left behind.
Choice of indicators can reveal or conceal gender inequalities
Choice of indicators determines the outcome of indices. For example, the overall HCI scores are higher for girls than for boys in most countries, but this is driven partly by the indicators chosen. The under-five mortality rate picks up women’s biological advantage in survival (for instance, in industrial countries where there is no discrimination against girls, the ratio of girls to boys for the under-five mortality rate is between 0.81 and 0.88) and the adult survival rate also favors women partly because of the greater number of deaths caused by violence and accidents among men in prime age groups.
Age-specific school enrollment rates and measures of quality of schooling are similarly those on which girls tend to score higher than boys but do not pick up gender inequalities in school completion, school-to-work transitions, or the segmentation and segregation of the labor market—all areas where men outperform women. Taken at face value, then, these findings would lead to the wrong conclusion that fewer investments are needed in women and girls when compared to men and boys to close productivity gaps in developing countries (when assessed against a benchmark of complete education and full health). A different choice of indicators would have yielded very different results.
Simplicity and clarity of message are needed for communication
Indices can drive change when used as communication tools to inform and influence. Reflecting on the utility of the suite of Human Development Report indices, Klasen concludes that they remain relevant because they changed the narrative on international development, from a narrow focus on boosting GDP to a holistic concept of human well-being. However, the original GII in this set of indices never took off because it had to be read alongside another index, the HDI. This made it too complicated, despite its solid conceptual underpinnings, and it needed substantial revision.
Simplicity is paramount, and indices work better and are more easily grasped when they focus on a single issue or domain. When an index tries to capture many different dimensions of women’s lives (or SDG goals and targets), values can move in opposite directions and cancel each other out (for instance, a loss in women’s security canceling a gain in their employment), leaving the headline figure unchanged and muddling the interpretation and the message.
It takes more than naming and shaming to move the needle
Indices can move the needle by pointing to clear policy interventions. The Ease of Doing Business Index (which began sex-disaggregating three labor market regulation indicators in 2017, although labor market regulations are not included in the 2019 index) has been most successful in driving response due to the clarity of required policy interventions. The index of the companion Women Business and the Law (under construction) has similar policy promise, though the underlying incentives for countries to improve their rankings may not be as strong.
If the proliferation of gender indices is the manifestation of increased interest in the well-being of women and girls in both the policy and data communities, this is of course to be welcomed. But to ensure that quantifying the problem is not used as a smokescreen for real action, both communities must ensure that methodological rigor and policy-oriented strategic thinking underpin any new addition to this landscape. Gender indices will be most useful if they convey a clear policy message.
 Klasen, S. 2018, Human Development Indices and Indicators: A Critical Evaluation, UNDP Human Development Report Office Background Paper, unpublished.