Methodology

Selection of variables

    Variables included in the SIGI 2019 were selected on the following criteria:

  • Conceptual relevance
    The variable should be closely related to the conceptual framework of discriminatory social institutions and measure what it is intended to capture.
  • Underlying factor of gender inequality
    The variable should capture an underlying factor that leads to unequal outcomes for women and men.
  • Data quality, reliability and coverage
    The variable should be based on high quality, reliable data. Ideally the data should be standardised across countries/territories and have extensive coverage across countries/territories.
  • Distinction
    Each variable should measure a distinct discriminatory institution and should add new information not measured by other variables.
  • Statistical association
    Variables included in the same dimension should be statistically associated, and thereby capture similar areas of social institutions without being redundant.

Country profiles

    The SIGI country profiles contain fully referenced qualitative information relative to social institutions, organised by dimensions. They were drafted following a standardised structure to ensure comparability across countries/territories in line with the following guidelines:

  • Conceptual relevance
    Qualitative information should be relevant to the conceptual framework of discriminatory social institutions.
  • Sources
    All information should be referenced and sourced from constitutions, legal frameworks, and primary publications, reports or studies, using the most recent data.
    Data should be sourced from and cross-checked with reliable studies, reports and publications, including country reports to the Convention on the Elimination of All Forms of Discrimination against Women, reports by international organisations and country sources.
  • Validation
    Country profiles were developed through a two-stage internal draft and review process. Qualitative information was validated by external gender experts with knowledge of the policy and legal landscape for gender equality and women’s rights at a national level (see list of experts in Acknowledgments).

The calculation of the SIGI is based on 46% of the 312 questions used for the country profiles. The SIGI and its dimensions are constructed according to the steps below.

Step 1: Building the Gender, Institutions and Development Database (GID-DB)
Truncating quantitative data at the equality benchmark and inverting the scale.
The SIGI and its sub-indices range from 0 for no discrimination to 1 for very high discrimination.
For some other variables, equality is reached at 0.5 instead of 1. Equality in political representation for example is achieved when 50% of parliament members are women. Hence, countries/territories having more than 50% of women have a score of 50%. According to the variables, the scale from no discrimination to very high discrimination is inverted to fit with the 0-1 scale. Hence, countries/territories having 50% of female members of parliament have a score of 0.
Assigning a score to qualitative variables
The qualitative information detailed in the SIGI country profiles are quantified using the following coding manual:

  • 0: The legal framework provides women with the same rights as men, without legal exceptions regarding some groups of women. There is no customary, traditional or religious laws or practices that discriminate against women’s rights.
  • 0.25: The legal framework provides women with the same rights as men, without legal exceptions regarding some groups of women. However, some customary, traditional or religious laws or practices discriminate against women’s rights.
  • 0.5: The legal framework provides women with the same rights as men. However, it does not apply to all group of women.
  • 0.75: The legal framework restricts some women’s rights.
  • 1: The legal framework fully discriminates against women’s rights.

In cases where no or insufficient information exists, variables are not assigned a value. The legal indicators are assessed based on all applicable legal frameworks, including civil law, religious law, customary law and traditional law.

Step 2: Constructing sub-indices
Some sub-indices are based on one variable while others on several. In the latter case, the sub-index is calculated only if all variables are assigned a value. For example:
Step 3: Aggregating sub-indices to build the dimensions

The dimensions aim to provide a summary measure of each area of discrimination. The dimension is calculated only if all sub-indices are assigned a value. For example:

Step 4: Computing the SIGI

The SIGI is a composite indicator built as an unweighted average of a non-linear of the dimensions.
The SIGI is calculated only if all dimensions are assigned a value.

 

Why exponentiate each dimension and sub-index?
• As SIGI is a multidimensional index, the use of this formulation helps investigate the trade-offs between the dimensions/sub-indices/variables.
• These trade-offs, however, are partial: an increase in inequality in one dimension/sub-index/variable can only be substituted partially by a decrease in inequality in another dimension/sub-index/variable.
• The magnitude of the increase of inequality is largest in the dimension/sub-index/variable where the country already performs poorly.
• While the SIGI 2014 used the “quadratic mean” formulation to compute the level of discrimination, the SIGI 2019 uses the exponential and logarithmic functions. This allows more variability in the rates of substitution between low levels and high levels of discrimination.
Why are the dimensions/sub-indices/variables equally weighted?
• Each dimension/sub-index/variable of discriminatory social institutions has equal value.
• No dimension/sub-index/variable is more important than another in terms of deprivation experienced by women.
How are the SIGI categories defined?
• The SIGI classification clusters 120 countries/territories into five levels of discrimination in social institutions: very low, low, medium, high and very high.

 

We are grateful to receive comments and advice from experts outside and within the OECD who participated in the 2016 Expert Group Meeting aiming at revising the SIGI 2019 conceptual and methodological frameworks. Our special thanks go to Eduardo Zambrano for his valuable contribution to the development of the SIGI methodology.