Methodology
The Sustainable Development Report 2023 provides an assessment of progress made towards the SDGs by all UN Member States. The Report includes the SDG Index, in which scores are presented on a scale of 0 to 100 and can be interpreted as a percentage towards optimal SDG performance. Therefore, the difference between 100 and a country’s SDG Index score is the distance, in percentage points, that must be overcome to reach optimum SDG performance. The same basket of indicators and similar performance thresholds are used for all countries, to generate comparable scores and rankings. To minimize missing-data bias, we do not calculate overall SDG Index scores or ranks for countries that are missing data on more than 20% of the indicators.
Substantial differences in rankings may result from small differences in aggregate SDG Index scores. This calls for caution when comparing country rankings. Differences of two or three positions between countries should not be interpreted as “significant”, whereas a differences of 10 places may be ascribed to meaningful differences in performance. For further details, see the statistical audit by Papadimitriou et al. (2019) conducted on behalf of the EU Joint Research Centre (JRC).
The SDG Dashboards provide visual representations of countries’ performance on the 17 SDGs. The “traffic light” color scheme (green, yellow, orange, and red) illustrates how far a country is from achieving a particular goal. The SDG Dashboards are presented for all countries where data permits, including those that are not included in the SDG Index. As in previous years, the SDG Dashboards and country profiles for OECD countries incorporate additional metrics that are not available for non-OECD members.
The SDG Trend Dashboards indicate whether a country is on track to achieve the goals by 2030, based on past performance. Trends are calculated for each indicator, building on annual growth rates since 2015 which are extrapolated to 2030. The country’s resultant indicator trends are then aggregated at the goal level, to give an indication of how it is progressing towards each SDG.
This section provides a summary of the methods used to compute the SDG Index and Dashboards. More information can be found online in SDG Index and Dashboards: Detailed Methodological Paper (Lafortune et al., 2018). In 2019, the Joint Research Centre (JRC) of the European Commission conducted an independent statistical audit of the report’s methodology and results, examining the conceptual and statistical coherence of the index’s structure. Their audit report and additional data tables are available on our website: www.sdgindex.org
Due to time lags in international statistics, this year’s edition does not capture most of the multiple impacts that the war in Ukraine has had on the SDGs, nor the impacts of other geopolitical and security crises that have emerged over the past 12–18 months. The data for Ukraine correspond to the situation before February 2022, as many data points have not been able to be updated since then. The inclusion of an indicator on exports of major conventional weapons should not be interpreted as a value judgment in the context of current conflicts, but rather as an effort to evaluate more generally the trend towards disarmament recognized by the United Nations and by civil society organizations as an important priority for peace, socio-economic stability, and sustainable development (UN Office for Disarmament Affairs, 2018; Amnesty International, 2008).
The 2023 SDG Index covers 166 countries. This year, the Report integrates further indicators that build on geographic information systems (GIS), to increase data availability and the timeliness of indicators related to access to road infrastructure and to key urban services. More information on these new geospatial indicators can be found in Part 3 of the report and in the online materials. This edition also incorporates one new spillover indicator – on modern slavery in international supply chains (Malik et al, 2022). Table A.1 summarizes these additions and identifies indicators that have been replaced or modified due to changes in the methodologies used and estimates produced by data providers. We have also introduced a refinement to the methodology used to evaluate trends for countries already exceeding SDG targets (explained in Section 3.A. below, the methodology overview).
For the first time, we present an overview of where the world as a whole stands on SDG progress, calculated using a population-weighted average for all UN Member States. Also included for the first time in this year’s edition is an estimation of the percentage of SDG targets that are on track to be met by 2030 for all countries with sufficient data to be included in the SDG Index. More details on this calculation can be found in Section 3.A.
Due to changes in the indicators and refinements in the methodology, SDG Index rankings and scores from one edition cannot be compared with the results from previous editions. However, Part 2 provides time series for the SDG Index, calculated retroactively using this year’s indicators and methods, providing results that are comparable across time. The full time series for the SDG Index are available for download online.
Despite our best efforts to identify data for the SDGs, several indicator and data gaps persist at the international level (Table A.2). Governments and the international community must increase investments in SDG data and monitoring systems, and build strong data partnerships to support informed SDG decisions and strategies.
To ensure the results are comparable across countries, we do not incorporate estimates received directly from national statistical offices. Data providers may adjust national data to ensure international comparability. As a result, some data points presented in this report may differ from data available from national sources. Moreover, the length of the validation processes of international organizations can lead to significant delays in publishing some data. National statistical offices may therefore have more recent data for some indicators than presented in this report.
The Sustainable Development Report provides a comprehensive assessment of distance from targets based on the most current data available covering all 193 UN Member States. This year’s report includes 97 global indicators, with 27 additional indicators included specifically for OECD countries (due to better data coverage in these countries).
The following sections provide an overview of the methodology used to select, normalize and aggregate indicators, and to generate indications of trends over time. Additional information is available online, including raw data, additional data tables and sensitivity tests.
Where possible, the Sustainable Development Report uses official SDG indicators endorsed by the UN Statistical Commission. Where there are data gaps or insufficient data for an official indicator, we include other metrics from official and unofficial providers. Five criteria for indicator selection were used to determine suitable metrics for inclusion in the report:
1. Global relevance and applicability to a broad range of country settings.
2. Statistical adequacy: The indicators selected represent valid and reliable measures.
3. Timeliness: The indicators selected are up-to-date and published on a reasonably prompt basis.
4. Coverage: There must be data available for at least 80% of UN Member States with a population greater than one million.1
5. Measurability of distance to targets: This must be able to be measured so that optimal performance can be determined.
Data sources
The data included in this report come from a mix of official and non-official sources. Most (around two thirds) are drawn from the databanks of international organizations (FAO, ILO, OECD, UNICEF, WHO, World Bank, and other sources) which follow extensive and rigorous data-validation processes. Other data sources (around one-third) include less traditional statistics, such as household surveys (Gallup World Poll), civil society organizations and networks (including Oxfam, Tax Justice Network, World Justice Project, or Reporters sans Frontières), peer-reviewed journals (for example, to track international spillovers) and geographic information systems (GIS). These non-official sources complement other data sources and help increase data availability and timeliness for key SDG indicators and targets. The full list of indicators and data sources is available online. The data for this year’s edition were extracted between February and April 2023.
To minimize biases from missing data, the SDG Index only includes countries that have data for at least 80% of the indicators or that have been in previous editions of the SDG Index and have data for at least 75% of the indicators. 2The list of countries not included in the SDG Index due to missing data is presented in Table A.3 below. We do, however, include all UN Member States in the SDG Dashboards and we feature country profiles for each one. These profiles also indicate any gaps in a country’s available SDG data.
Due to the lack of widely accepted statistical models for imputing country-level data for many SDG priorities, we do not generally impute or model missing data apart from a few exceptional circumstances. The list of indicators where imputations have been performed is available online in the Codebook.
The procedure for calculating the SDG Index comprises three steps: (i) establish performance thresholds and censor extreme values from the distribution of each indicator; (ii) rescale the data to ensure comparability across indicators (normalization); (iii) aggregate the indicators within and across SDGs.
Establishing performance thresholds
To make the data comparable across indicators, each variable was rescaled from 0 to 100 – with 0 denoting the worst performance and 100 describing the optimum. Rescaling is sensitive to the choice of limits, as extreme values (outliers) risk becoming unintended thresholds that can introduce spurious variability in the data. Consequently, the choice of upper and lower bounds can affect the relative ranking of countries in the index.
The upper bound for each indicator was determined using the following decision tree:
1. Use the absolute quantitative thresholds of the SDGs and targets: e.g., zero poverty, universal school completion, universal access to water and sanitation, full gender equality.
2. Where no explicit SDG target is available, apply the principle of “leave no one behind” to set the upper bound to universal access, or zero deprivation.
3. Where science-based targets exist that must be achieved by 2030 or later, use these to set the 100% upper bound (e.g., zero greenhouse gas emissions from CO₂ as required by no later than 2050 to limit global warming to 1.5°C, 100% sustainable management of fisheries).
4. For all other indicators, use the average of the top five performers.
These principles interpret the SDGs as “stretch targets” and focus attention on those indicators where a country is lagging behind. The lower bound was defined at the 2.5th percentile of the distribution. Each indicator distribution was censored, so that all values exceeding the upper bound scored 100, and values below the lower bound scored 0.
Normalization
After establishing the upper and lower bounds, variables were transformed linearly to a scale between 0 and 100 using the following rescaling formula for the range [0; 100]:
Image A.1 | Rescaling equation
where x is the raw data value; max/min denote the upper and lower bounds, respectively; and x’ is the normalized value after rescaling.
The rescaling equation ensured that all rescaled variables were expressed as ascending variables (i.e., higher values denoted better performance). In this way, the rescaled data became easy to interpret and compare across all indicators: a country that scores 50 on a variable is halfway towards achieving the optimum value, whereas a country with a score of 75 has covered three quarters of the distance from worst to best.
Weighting and aggregation
Several rounds of expert consultations on earlier drafts of the SDG Index made it clear that there is little consensus across different epistemic communities on assigning higher weights to some SDGs over others. As a normative assumption, we therefore opted to assign a fixed, equal weight to every SDG, to reflect policymakers’ commitment to treat all SDGs equally and as an integrated and indivisible set of goals. This implies that countries need to pay attention to all goals to improve their SDG Index score, but focus particularly on those where they are furthest from achieving the SDGs and where incremental progress might therefore be expected to be fastest.
To compute SDG Index scores, we first estimate scores on each goal using the arithmetic mean of indicators for that goal. These goal scores are then averaged across all 17 SDGs to obtain the final Index score. Various sensitivity tests were carried out, with the results available online, including comparisons of arithmetic mean versus geometric mean and Monte-Carlo simulations at the Index and Goal level. Monte-Carlo simulations call for prudence in interpreting small differences between countries’ Index scores and rankings, however, as these may be sensitive to the weighting scheme.
Dashboards
We introduced additional quantitative thresholds for each indicator to group countries in a “traffic light” table. Thresholds were established based on statistical techniques and through various rounds of consultations with experts conducted since 2016.
Averaging across all indicators for an SDG might hide areas of policy concern if a country performs well on most indicators but faces serious shortfalls on one or two metrics within one SDG (this is often referred to as the issue of “substitutability” or “compensation”). This applies particularly to high-income and upper-middle-income countries that have made significant progress on many SDG dimensions but may face serious shortfalls on individual variables, for example on the sustainability of diets and agriculture within SDG 2.
As a result, the SDG Dashboards focus exclusively on the two variables on which a country or region performs worst. To this end, the indicator values were first rescaled from 0 to 3 according to how they compared to the thresholds. Values worse than the red threshold were rescaled (using a min-max formula) from 0 to 1 where 0 corresponds to the lower bound and 1 to the value of the red threshold. Values better than the green threshold were rescaled from 2 to 3 where 2 corresponds to the value of the green threshold and 3 to the upper bound. The values between these two thresholds were similarly rescaled, and for all indicators the yellow/orange threshold was set as the value halfway between the red and green thresholds (1.5 after rescaling). Each interval between 0 and 3 is continuous. We then took the average of the two rescaled variables on which the country performed worst to identify the rating for the goal. We added the rule that a red rating is applied only if both the worst-performing indicators score red. Similarly, to score green, both of the best-performing indicators must be green. If the country has less than 50% of the indicators available under a goal the dashboard color for that goal is “grey”. The quantitative thresholds used to generate the dashboards are available in Table A.5.
SDG Trends
Using historic data, we estimate how fast a country has been progressing towards an SDG and determine whether – if extrapolated into the future – this pace will be sufficient to achieve the SDG by 2030. For each indicator, SDG achievement is defined by the green threshold set for the SDG Dashboards. The difference in percentage points between the green threshold and the normalized country score denotes the gap that must be closed to meet that goal. To estimate trends at the indicator level, we calculated the linear annual growth rates (annual percentage improvements) needed to achieve the target by 2030 (growth from 2015 to 2030), which we compared to the average annual growth rate over the most recent period since the adoption of the SDGs in 2015 (2015–2022). Progress towards achievement on a particular indicator is described using a four-arrow system (Figure A.1). Figure A.2 illustrates the methodology graphically. Because time-series data is required for these calculations, indicators with only one or very few data points across time could not be used for these analyses. The list of indicators used to generate the trend indications is available in Table A.6.
To estimate the overall trend for an SDG, each indicator trend was assigned a value on a scale from 0 to 4 based on its growth rate. Indicators with decreasing growth rates were rescaled (using a min-max formula) from 0 to 1 where 0 corresponds to the worst decrease across countries on an indicator and 1 corresponds to an absolute stagnation over time (growth rate of 0). Increasing growth rates were similarly rescaled into intervals of 1 to 2, 2 to 3, and 3 to 4, where 2 corresponds to half the growth rate necessary to achieve the green threshold, 3 corresponds to exactly the growth rate needed to achieve the green threshold, and 4 to the highest growth rate among the countries on a given indicator. Each of the four intervals between 0 and 4 is continuous. The trend for an SDG was calculated as the arithmetic average of all the re-scaled values of the trend indicators for that goal. An average between 0 and 1 corresponds to a “decreasing” goal trend, between 1 and 2 to a “stagnating” goal trend, between 2 and 3 to a “moderately improving goal trend”, and finally between 3 and 4 to an “on track” goal trend. Overall goal trends were not calcu- lated for countries missing a goal-level dashboard.
Since the projections are based on past growth rates over several years, a country might have observed a decline in performance in the past year (for instance due to the impact of COVID-19) but still be considered as being on track. This methodology emphasizes long-term structural changes that have occurred since the adoption of the SDGs in 2015, rather than focusing on annual changes that may be temporary or cyclical. This year we introduced a refinement to the methodology whereby countries that currently exceed the target for an indicator but have seen a decrease since 2015 are assigned an orange arrow. This is because if the decreasing trend continues, the country may no longer meet the SDG target in the future.
Status of SDG targets
In this year’s edition, we introduce an assessment of the status of SDG targets both for every country and for the world overall. We based this assessment solely on trend indicators (Table A.6) since time-series data was needed to calculate rates of progress. Indicators that we featured in the Index and country profiles for OECD countries only were excluded from this global calculation, to provide comparable results across countries.
Where the past rate of progress is sufficient to meet the target by 2030 (corresponding to the green arrow “On track or maintaining SDG achievement”) the indicator was counted as being on track. Indicators where past rates of progress will be insufficient to meet the SDG target (corresponding to the orange “stagnating” or yellow “moderately improving” arrows) were counted as showing limited progress. Finally, indicators heading in the wrong direction (the red “decreasing” arrow) were counted as worsening. Indicators for which a country has already met the target but has decreased its score since 2015 were also considered to be worsening. For the assessment of the status of SDG targets for the World (population-weighted average), we only considered as on track those indicators that showed consistent progress both in the long term (since 2015) and in the short term (since 2019 or 2020).
Note: The inclusion of an indicator on export of major conventional weapons should not be interpreted as a value judgment on the context of current conflicts but rather as an effort to evaluate more generally the trend towards disarmament recognized by the UN and civil society organizations as an important priority for peace, socio-economic stability and sustainable development (UN Office for Disarmament Affairs, 2018; Amnesty International, 2008).
Source: Authors' analysis
The Sustainable Development Report (formerly the SDG Index & Dashboards) is a global assessment of countries' progress towards achieving the Sustainable Development Goals. It is a complement to the official SDG indicators and the voluntary national reviews.
All data presented on this website are based on the publication Sachs, J.D., Lafortune, G., Fuller, G., Drumm, E. (2023). Implementing the SDG Stimulus. Sustainable Development Report 2023. Paris: SDSN, Dublin: Dublin University Press, 2023. 10.25546/102924
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