1. Introduction
The 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs) call for nations to become more sustainable, ensuring the social inclusion of all. The Agenda is a global action plan for building resilient societies and promoting sustainable development. In particular, SDG10 of the Agenda aims to reduce inequalities among and within countries in many dimensions, mainly those related to income but also those related to age, race, disability, sex, origin, religion, economic status, etc. The importance of that goal arises from the fact that large disparities negatively affect sustainable development and slow down progress towards achieving the rest of the SDGs. The latter conclusion resulted from the fact that progress made in achieving one goal impacts the outcomes of other goals. In this context the 2030 Agenda expresses the interlinked nature of SDGs [
1]. Moreover, the large scale of inequalities hampers social cohesion and reduces equal access to education and health services or negatively impacts social inclusion.
The motivation of the study is related to analysis of the selected socioeconomic variables that may affect the progress in reducing inequalities in the EU. Moreover, the study shows an attempt to analyze the (dis)similarities of the EU countries with respect to the variables to assess the progress of these countries with regard to SDG10 of the 2030 Agenda. The need for such analysis is confirmed in the literature. Many studies analyze the similarities of EU or OECD countries concerning the different SDGs or different strategies. The progress towards achieving the targets of the Europe 2020 Strategy has been studied by, for example, [
2,
3,
4,
5,
6,
7]. These papers offer different multivariate methods to support the recognition of the paths and to formulate conclusions, including, among others, cluster analysis [
5,
6] or by building rankings of analyzed countries see, e.g., [
3]. The performance of the SDGs or selected components has been analyzed by [
8,
9,
10,
11]. Many studies consider the general performance of the SDGs, including a large set of indicators applied for a group of countries see, e.g., [
9] using multivariate methods. Some studies analyze single countries, an example of which is [
10], who focus on the case of Spain. The conclusion is that Spain requires urgent policies in order to fulfill the standards in sustainability by the year 2030. The study in [
12] provides an interesting analysis of the Spanish synergies and trade-offs among the SDGs, calculating the correlation between a reduced set of indicators representing each SDG. The empirical results make it possible to conclude that almost 80% of the significant interactions can be classified as synergies or trade-offs. The EU labor market inequalities, reflected by the specific indicators proposed for Sustainable Development Goal 8, are analyzed by, e.g., [
13]. A similar analysis, presented in [
14], concerns the role of the SDGs from the point of view of targets aimed at health and well-being.
Despite this, there is a lack of similar analyses of SDG10, even though that SDG plays an important role in the structure of the Agenda. It seems that the difficulties in providing similar analyses may be a result of the limited access and availability of all SDG10 indicators at a country-specific level. As a result, in this paper, the list of available SDG10 indicators is extended by a set of variables that may affect the levels and dynamics of inequalities among and within countries. Thus, the similarities of countries are analyzed on the basis of an alternative set of variables to the set consisting of only SDG10 indicators.
Considering the motivation, the goal of the study is twofold. Firstly, the aim of the study is to assess the dynamics of the EU27 with regard to SDG10 by analyzing appropriate indicators attributed to that SDG. Secondly, the paper investigates the (dis)similarities of the EU countries with respect to the variables that may affect the levels of the inequalities or the progress towards reducing these inequalities. Due to the limited availability of SDG10 indicators at a country-specific level, the analysis (under this goal) is prepared through the use of an alternative set of variables monitoring the socioeconomic conditions of the economies. In order to achieve the goal, multivariate statistical methods are applied. The methods include cluster analysis and the linear ordering method, supplemented by the principal component analysis (PCA). All data derive from Eurostat, and the timeframe (due to data availability for all 27 countries) covers the period 2010–2019. The contribution and novelty of the study are also supported by the analysis of the progress in achieving SDG10 in the EU context in the medium-term and its wider linkage with the socioeconomic conditions of the EU economies using multivariate methods, including cluster analysis, linear ordering and built ranking of countries, and PCA.
The structure of the paper is as follows. The next section provides general information on the origins of the 2030 Agenda and the importance of SDG10. The third section presents insights derived from an analysis of the SDG10 indicators related to three dimensions of the sustainable goal. Thereafter, the data and the methods of multivariate analysis are presented, while in the fifth section the results are presented. The sixth section provides the discussion, while the last section presents the general conclusions.
2. The 2030 Agenda and Sustainable Development Goal 10—Reduce Inequality within and among Countries
In 2015, the United Nations General Assembly adopted the document of the post-2015 development agenda: “Transforming our world: The 2030 Agenda for Sustainable Development” [
15]. The preamble of the document outlines that the Agenda is an ambitious plan of actions aimed at achieving sustainable development by means of improvement in areas related to people, the planet, prosperity, peace and partnership [
15]. The integral element of the 2030 Agenda is that of a set of 17 Sustainable Development Goals (SDGs) and 169 targets, which were adopted during the UN Summit in September 2015 by all United Nations member states. As assumed in [
15], successful realization of the SDGs will impact everyone and transform the world into a better place. The timeframe for achieving a meaningful improvement was set at 15 years (i.e., by 2030). The aforementioned integrated goals of the SDGs are assigned to the following areas: SDG1—End poverty in all its forms everywhere; SDG2—End hunger, achieve food security and improved nutrition and promote sustainable agriculture; SDG3—Ensure healthy lives and promote well-being for all at all ages; SDG4—Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all; SDG5—Achieve gender equality and empower all women and girls; SDG6—Ensure availability and sustainable management of water and sanitation for all; SDG7—Ensure access to affordable, reliable, sustainable and modern energy for all; SDG8—Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all; SDG9—Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation; SDG10—Reduce inequality within and among countries; SDG11—Make cities and human settlements inclusive, safe, resilient and sustainable; SDG12—Ensure sustainable consumption and production patterns; SDG13—Take urgent action to combat climate change and its impacts; SDG14—Conserve and sustainably use the oceans, seas and marine resources for sustainable development; SDG15—Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss; SDG16—Promote peaceful and inclusive societies for sustainable development, provide access to justice for all and build effective, accountable and inclusive institutions at all levels; SDG17—Strengthen the means of implementation and revitalize the global partnership for sustainable development. The SDGs derive from experience related to the realization of the Millennium Development Goals because the SDGs were built upon the Millennium Development Goals adopted in 2000 by the United Nations General Assembly in the outline declaration entitled the United Nations Millennium Declaration [
16]. The deadline for reaching the targets of the eight Millennium Development Goals was set at 2015; thus, the SDGs are elements of a new plan set for the 15 years following the previous deadline for the Millennium Development Goals global action plan. In order to analyze the progress made in achieving the SDGs, there is a need for monitoring the realization of the targets. For this purpose, the UN launched the High-level Political Forum on Sustainable Development (which is responsible for reviewing the 2030 Agenda at the global level). It was mandated in 2012 via the document of the United Nations Conference on Sustainable Development (Rio + 20), i.e., “The Future We Want” see [
17], whereas the organizational issues are outlined in General Assembly Resolution 7/290 see [
18]. The UN Conference on Sustainable Development (Rio + 20) was an important milestone in building the frameworks of the Agenda. Additional arrangements concerning following up on and reviewing the Agenda at the global level are outlined in General Assembly Resolution 70/290 see [
19]. As a result, in order to measure the progress towards achieving the SDGs, a set of indicators were designed and adopted (list of 232 indicators) in July 2017 by the United Nations General Assembly in Resolution 71/313 see [
20]. These indicators were developed by the Inter-agency and Expert Group on Sustainable Development Goal Indicators [
20]. Resolution 71/313 defines the indicators for each goal and target of the Agenda [20, Annex]. The Resolution [
20] assumes that indicators will be reviewed comprehensively by the Statistical Commission during its 51st session (in 2020) and 56th session (in 2025). The indicator list revised in 2020 is built from 231 different indicators (the global indicator framework for the SDGs includes 247 indicators due to 12 indicators being repeated under more than one different target)—see [
21]. The assessment of trends in the indicators against the targets defined for each SDG allows analyzing the progress made in achieving the goals of the 2030 Agenda.
In the case of the EU, the progress towards the SDGs is regularly monitored by Eurostat on the basis of the set of EU SDG indicators. In the EU context, the set for the 17 SDGs comprises 100 indicators, but 36 of them are multipurpose (used to monitor more than one SDG). Generally, Eurostat proposes monitoring each goal via six indicators primarily attributed to the SDG, except for SDG14 and SDG17—both of which have only five attributed indicators [
22].
In this study, special attention is paid to Sustainable Development Goal 10 (which calls for reducing inequalities within and among countries). Detailed information on the targets and indicators attributed to SDG10 is presented in
Table 1 below.
The SDG10 is attributed to the prosperity area of the 2030 Agenda [
24]. SDG10 has 10 important targets and their realization is monitored via the use of indicators originally presented in UNGA Resolution 71/313. Taking into account the ambition of the 2030 Agenda, SDG10 calls for reducing inequalities and promoting the political, social and economic inclusion of all. The goal strongly focuses on ensuring sustainable development (which is assumed to be inclusive, more equal, and resilient to unexpected changes and events). The progress towards transforming the world into one that is more equal affects the actions taken to reduce inequalities in many dimensions, including income, age, gender, ethnicity, religion, and others, such as a reduction in between-country inequalities and within-country inequalities. Furthermore, an important issue is related to migration and migrants, particularly the 2030 Agenda and the SDG10 aim of ensuring the facilitation of safe migration. As a result, SDG10 focuses on reducing inequalities within and among countries and encompasses a strong orientation towards the social inclusion of all.
The importance of SDG10 increased in the context of the COVID-19 pandemic. This is due to the fact that, on the one hand, the pandemic has deepened inequalities, especially in the socioeconomic context; on the other hand, existing inequalities and those that have not been eliminated have amplified the negative effects of the pandemic. The United Nations emphasize that the most vulnerable groups of people being hit the hardest by the pandemic are older persons, persons with disabilities, children, women, migrants, and refugees [
25].
4. Methods and Data—Empirical Analysis of the EU Countries
The aim of SDG10 is to achieve significant sustainable improvement in the quality of life, well-being, and socioeconomic situation of people all over the world by reducing inequalities. In this section an attempt to analyze the (dis)similarities of European Union countries with respect to the selected socioeconomic variables affecting SDG10 and its indicators is analyzed. The comparison allows for an assessment of the socioeconomic conditions of the EU member states considered, mainly via the implementation of the SDG10 indicators and analyzing the inequalities.
4.1. Methods
The previous section presents a general overview of the situation of the EU27 as a whole in the context of SDG10 and inequalities. The analysis of indicators confirms the existence of disparities. The aim of this section is to analyze and compare EU countries in the context of the development of SDG10 indicators and other socioeconomic variables and assess the potential (dis)similarities between the economies. That goal is achieved through the use of multivariate statistical methods, especially the hierarchical grouping method (which is a cluster analysis). Moreover, the ordering of countries with respect to the set of chosen variables is proposed as an additional supplementary analysis and it is presented in the form of ranking, where the approach used is Hellwing’s linear ordering method.
The advantage of the agglomeration technique is that it allows joining objects which are very similar into clusters. In general, the algorithm of cluster analysis is based on the analysis of the distance between objects [
27], and the greater the distance between objects, the lower the level of similarity that they exhibit. As a consequence, an important step in cluster analysis is to compute distances between objects, i.e., to compute a distance for each pair of objects
and
, in order to quantify their degree of dissimilarity [
28]. In practice there is a set of different distance measures, with the most popular choice being the Euclidean distance [
28,
29]. In this study, the distance is also determined on the basis of Euclidean metrics, as represented by Formula (1):
where
and
are, respectively, the
kth variable value of the p-dimensional observations for individuals
i and
j [
28].
Furthermore, in the presented approach, Ward’s method [
30] is employed in order to measure the proximity between groups of individuals. In this method the distance between clusters is defined as an increase in the sum of squares within clusters [
29,
31]. The advantage of Ward’s method is that it is generally used with (squared) Euclidean distances [
32]. However, it can also be used with any other (dis)similarity measure [
32].
The graphical outcome of the used approach is a dendrogram (which allows for analyzing the structure of clusters).
The proposed method for ordering countries is Hellwing’s [
33] approach. The idea behind the method is to determine a pattern (ideal) object, i.e., an abstract, ideal object with the best features (computed via the use of minimum values for destimulants and maximum values for stimulants). The opposite of a pattern object is an anti-pattern object, i.e., an object constructed on the basis of the maximum values for destimulants and the minimum values for stimulants. To determine the order of countries, the taxonomic distance from the standardized object (
) to the pattern object (
) is calculated through application of the Euclidean metric, whose formula, under the assumption of the approach, is as follows:
The location of the
i-th object with respect to the pattern is recognized on the basis of the measure of distance
, which is often known as the development measure, and its formula is as follows:
where:
, and
denotes the arithmetic mean of distance
, and
denotes the standard deviation of distance
. The development measure equals 1 for the pattern object and 0 for the anti-pattern object, and it is generally assumed that
∈ [0;1] see [
34]. As a result, the set of analyzed objects can be divided into three groups (e.g., I group, II group, III group), depending on the size of
. The objects for which
≥
can be recognized as best performers in the context of the analyzed set of variables, while the objects for which
≤
are objects with low realization of the variables [
35]. The range
) is calculated via the use of the following formula (4):
where:
is the arithmetic mean of measure
, and
is the standard deviation of measure
.
In this paper, cluster analysis is applied as the main tool to compare EU countries regarding their socioeconomic conditions and the problem of reducing inequalities in the context of SDG 10. The approach used allows for investigating the (dis)similarities of the European economies, and in this study, it is employed only for the uncorrelated variables.
However, in the proposed analysis, an additional multivariate approach, the principal component analysis (PCA), is applied to the large (whole) set of selected socioeconomic indicators used in this study. In the context of the potential collinearity of the large set of data, the PCA makes it possible to create a smaller number of linear combinations of the initially analyzed set of indicators see, e.g., [
36,
37,
38]. Generally, PCA is a method to reduce dimensionality, and it makes it possible to determine a number of components that account for the maximum variance in the dataset. The possibility of using all variables may be seen as a strong advantage of the method. As a result, the PCA approach aims to reduce the limitations of the direct use of cluster analysis to the original dataset caused by the possible collinearity of the variables. In this context, the advantage of the PCA is that it is possible to use a large set of data, regardless of the problem of correlation. In other words, the PCA method makes it possible to transform a large set of variables into a small set of uncorrelated variables, i.e., principal components. According to the algorithm, the first obtained principal component accounts for the highest variability in the data, and each subsequent component accounts for as much of the remaining variability as possible, etc., (see, e.g., [
36,
39]), and it is signified by the value of variance. However, in the final analysis, it is useful to not take all components, but reduce the dimension and take into consideration the first
k-number of components, which explains to a good level a predetermined or desired threshold of the total variability. In this study, it was decided to use Kaiser’s approach [
40] to choose the appropriate number of eigenvectors, including the first two principal components that will be considered. As mentioned, in this study, the PCA is used only as a supplementary method that makes it possible to prepare an additional point of view of the large dataset used, and it is only adapted as a complementary tool regarding the cluster analysis, and only for the year 2019.
4.2. Data
The analysis is based on a group of 27 EU countries and, as explained in previous sections, in the case of SDG10 indicators it focuses only on variables that are available for all countries. As a result, the time sample covers the period 2010–2019. In order to compare (dis)similarities between countries, and especially to analyze the potential convergence of the EU countries, separate analyses are provided for the years 2010 and 2019. The data source is the Eurostat database. Taking into account the goal of the study, only the indicators available for all 27 EU countries are considered in both years. Due to the fact that some of the SDG10 indicators describing the situation of the EU population (considered from the perspective of citizenship) are not available (mainly for non-reporting EU countries), the decision was made to use general indicators available for reporting EU countries (instead of the citizenship gap for the indicators). Furthermore, the applied methodology requires variables to be expressed as ratios, which affects the proper choice of variables. All of these requirements affect the list of potential indicators that can be included in the analysis. Finally, the detailed analysis of the availability and quality of SDG10 indicators in 2010 and 2019 impacts the decision to consider the following variables:
—employment rate, only for reporting countries, instead of the citizenship gap (% of population aged 20 to 64),
—young people neither in employment nor in education and training (NEET), only for reporting countries, instead of citizenship gap (% of population aged 15 to 29),
—early leavers from education and training, only for reporting countries, instead of citizenship gap (% of population aged 18 to 24),
—people at risk of income poverty after social transfers, only for reporting countries, instead of citizenship gap (% of population aged 18 years or more),
—purchasing power adjusted GDP per capita, index EU27 = 100,
—relative median at-risk-of-poverty gap (% distance to poverty threshold),
—income distribution (quintile share ratio),
—income share of the bottom 40% of the population (% of income).
However, due to potential collinearity between these variables and its consequences for the reduction in the list of variables used in final analyses, additional socioeconomic conditions that may affect the scale of inequalities are included. The extension includes the following control variables for the socioeconomic performance of the EU countries:
—Gini coefficient,
—spending on social protection, % of GDP,
—proportion of population aged 80 years and more,
—proportion of population aged 65 years and more,
—young-age dependency ratio,
—old-age dependency ratio,
—total age dependency ratio,
—purchasing power adjusted GDP per capita growth rate, %.
Selected descriptive statistics for the years 2010 and 2019 are presented in
Table A1 and
Table A2 in
Appendix A. What is more, the set of chosen variables were evaluated while taking into account their informative features. It is important that the set of variables utilized should be characterized by a low degree of correlation (in order to avoid collinearity). The correlation matrices for indicators are presented in
Table A3 and
Table A4 in
Appendix A. The literature points out that, generally, the correlation between variables should not be strong [
41] and that the practice is to use variables with coefficients not exceeding 0.7 [
42]. Moreover, in this study there is an assumption that the same set of variables needs to be compared in both years. Therefore, the collinearity in one year affects the decision regarding the reduction of the list of variables in the second year. Such an assumption allows for comparing the same set of features of the economies in both years. The consideration of all requirements and conclusions based on the correlation matrix meant that the final set of variables used in both years is as follows:
—employment rate, only for reporting countries, instead of the citizenship gap (% of population aged 20 to 64),
—early leavers from education and training, only for reporting countries, instead of citizenship gap (% of population aged 18 to 24),
—purchasing power adjusted GDP per capita, index EU27 = 100,
—income distribution (quintile share ratio),
—spending on social protection, % of GDP,
—young-age dependency ratio,
—old-age dependency ratio.
Before further analyses, the variables were standardized. Variables , , , and are related to the SDG indicators, but it should be reminded that variables and reflect data only for reporting countries, not a citizenship gap. Moreover, in this study it is assumed that the ranking of countries is built only for data closely related to the SDGs, i.e., on the basis of the application of variables , , , and .
In the case of the PCA, after standardizing the set of 16 variables, all 16 were used. The analysis, as a supplementary tool, is applied only to the large dataset available for 2019.
5. Results
The analysis of the EU27 countries with respect to the similarities in socioeconomic backgrounds in the light of the 2030 Agenda is the objective of this session. The outcomes of the used algorithm are presented in the form of dendrograms.
Firstly, cluster analysis of the variables related to SDG10 is carried out in both years in Euclidian space. The dendrograms for the baseline method (i.e., Ward’s method) for the years 2010 and 2019 are presented below (see:
Figure 10).
The graphical outcome indicates the division of the countries into two big groups that, under the assumption, differ mostly. In 2010 the first group includes Malta, Italy, Portugal, Spain, Poland, Croatia, Greece, Estonia, Lithuania, Latvia, Romania, and Bulgaria, whereas in 2019 the separate group comprized only Italy, Romania, Spain, and Bulgaria. The conclusion of that observation is that the big dissimilarities of the EU countries in the context of the applied set of variables between 2010 and 2019 are maintained with respect to Italy, Romania, Spain, and Bulgaria in comparison to the rest of the EU. This is due to the fact that between 2010 and 2019 a shift of Malta, Portugal, Poland, Croatia, Greece, Estonia, Lithuania and Latvia is observed with respect to the realization of the four variables analyzed. However, the analysis of the dendrograms and a more detailed analysis of the data emphasize the significant outlier position in 2010 of Luxembourg and in 2019 of Luxembourg and Ireland, which is affected by the variable. Thus, the variable was excluded from the list of indicators, and new dendrograms were generated. The results are presented below.
The analysis emphasizes the maintenance of disparities between Italy, Romania, Bulgaria, and Spain and the rest of the European Union countries. Elimination of the
variable, which drives the outlier position of a few countries, slightly changed the structure of clusters but allows for further analyses of the dendrograms, especially as Ward’s approach is assumed to be quite sensitive to the outliers (which can impact the results) [
32]. The next step is to divide the dendrograms into clusters in order to determine the most similar groups of countries.
Figure 11 makes it possible to divide the dendrogram for 2010 into five clusters and the dendrogram for 2019 into six clusters of the most similar countries with respect to the variables analyzed. The structures of the arbitrary extracted clusters are presented in detail in
Table 3.
The comparison of the structures of extracted clusters suggests that Latvia and Lithuania in both years create a separate cluster, but in 2019 the two countries were more similar to the rest of the EU than Italy, Romania, Spain, and Bulgaria (which created an outermost linkage with the remaining 23 countries). It may suggest that the inequalities between the group of the aforementioned four countries and the rest of the EU are maintained or even deepened (in the context of the analyzed set of variables). The structure of the clusters points out the similarity of the Netherlands, Czechia, Sweden, and Finland in both years. Countries like Belgium, France, Ireland, Cyprus, and Poland are (together) elements of one cluster in both years. The descriptive statistics for each cluster inform that in 2010, cluster 1 was characterized by the highest intra-cluster average for variable —income distribution. Therefore, it denotes that in 2010, Latvia and Lithuania had the highest income inequality (as analyzed from the point of view of the income distribution variable) in comparison to the rest of the clusters. In 2010, the highest intra-cluster average for variable was observed in cluster 3, whereas the highest average for and a quite high average for were observed in cluster 2. In 2019, cluster 1 was created from countries for which the intra-cluster average for and the intra-cluster average for were the highest. In cluster 5 the intra-cluster average for and for were the lowest, whereas in cluster 6 the average was the lowest for .
Application of the linear ordering method enables ordering countries with respect to realization of the variables. The division into three groups of countries, analyzed with respect to the computed values for
, and
is shown in
Table 4.
Computing values , , and separately for each year allows dividing the countries with respect to realization of the analyzed set of variables. As presented, the group with weak realization of the variables in comparison to the pattern in both years consists of four countries, but only Spain is attributed by the approach to the I group in both years. The numbers of countries in the group of the best performers (i.e., group III) in both years differ, consisting of six countries in 2010 and four countries in 2019, but in both years the group includes the Netherlands, Czechia, and Sweden. In 2010 the disparity in development measure between the “worst” country and the “best” country is around 0.854, whereas in 2019 it is around 0.768. This implies a reduction in disparity between two extreme countries. Sweden in 2010 was computed as being a country closer to the ideal pattern (due to the value being closer to 1 in 2010 than in 2019). Sweden and Czechia are attributed by the linear ordering method as being the best performers, but the disparity between these countries (as measured via ) was lower in 2010 (the distance is around 0.025 in 2010 and 0.058 in 2019). On the other hand, the difference in between the “worst” and the second-worst countries was higher in 2010 than in 2019. In 2010, Spain held the second-to-last place and in 2019 the fourth, but its position in 2019 was closer to the anti-pattern due to the lower value of . Moreover, in 2010 the difference between two distinguished best performers was lower than the difference between two worst performers—the opposite situation was in 2019.
Finally, the outcome generated on the basis of Ward’s method and the squared Euclidian distance for a set of all variables is presented in
Figure 12. Due to the impact of the
variable on the outlier positions, the variable, as previously, was excluded from the dataset.
The analysis of the dendrograms affects, as previously, the decision to distinguish the clusters, whose structures are presented in
Table 5.
The comparison of the structure of clusters indicates that in both years, Romania, Spain, Malta, and Bulgaria are included in the first “big” cluster, exhibiting persistent derogation from the rest of the EU countries. Furthermore, in both years, Malta, Romania, and Spain are structured in one cluster. A similar conclusion can be formulated in the cases of Sweden, Finland, and Denmark—these countries are elements of one cluster in both years. In 2010, cluster 1 was characterized by countries whose intra-cluster average of variable was the highest. The highest intra-cluster average for cluster 2 concerned variable (highest income inequality), whereas the lowest was observed for and . Cluster 3 had the highest average for and the lowest for and , whereas the highest intra-cluster average for was seen in cluster 6. The lowest intra-cluster average for variable was observed in cluster 5, for which the averages for and were the highest among all six extracted clusters. In the case of 2019, cluster 1 was characterized by countries with the lowest intra-cluster average for and and the highest average for . Cluster 2 was characterized by a high intra-cluster average for and and the lowest average for . The highest intra-cluster average for and and the lowest average for were observed in the case of cluster 5 (grouping Sweden, Finland, Denmark, France, and Belgium).
The PCA method makes it possible to reduce the dataset dimensionality. As mentioned previously, the initial set of potentially correlated variables is used. The presented analysis is based only on 2019. This procedure makes it possible to obtain the principal components and eigenvalues, presented in
Table 6 below.
The first component identifies around 38% of the total variance, whereas the sum of the first and second components identifies about 60% of the total information included in the initial variables. However, an important step in this method is to decide on the number of components to be potentially taken into account in any further analysis. As mentioned, in this study, Kaiser’s [
40] approach is adopted, and as a result, the first five components are taken for further considerations. The amount of the variance retained by the first five components is around 87%. As a result, in the further analysis, the number of components was reduced to the first five components by losing only around 13% of the information included in the initial set of variables. The transformation of the set of variables into a set of components makes it possible to illustrate multivariate data.
Table 7 shows the coefficients of the components.
The additional analyses of the PCA results indicate that the first component is mainly affected by the information loaded by variable, the second—by variable, the third by, the fourth by and the fifth by. The results are interesting because they confirm the final set of uncorrelated data included in the multivariate methods (see the description of the result for the cluster analysis and the linear ordering method).
Figure 13 below shows the indicators in the PCA on the correlation circle according to the first two principal components.
The circle indicates the outlier position of the
variable—purchasing power adjusted GDP
per capita, index EU27 = 100, which was also recognized in previous analyses, based on the linear ordering method and cluster analysis.
Figure 13 shows a group of indicators. For example, one of the visible groups consists of the variables
—the proportion of the population aged 80 years and more,
—the proportion of population aged 65 years and more,
—the old-age dependency ratio, and
—the total age dependency ratio, i.e., variables mainly related to the “old” population. It is also possible to include variable
—spending on social protection as a% of GDP, which is correlates more with the “older” than “younger” structure of the population. The second visible group concerns indicators related to variable
—people at risk of income poverty after social transfers, (indicator only for reporting countries, instead of citizenship gap, as used previously (% of population aged 18 years or more),
—the relative median at-risk-of-poverty gap (% distance to poverty threshold),
—income distribution (quintile share ratio), and
—the Gini coefficient. When comparing countries, the dimension that involves the two first components confirms the disparities between EU countries. The PCA method applied for the 2019 dataset investigates disparities between countries, emphasizing the outlier position of the euro area peripheral countries (Italy, Greece, and Portugal) and also the outlier position of Romania and Bulgaria. The results also allow us to conclude about the division of the analyzed countries based on whether they are “new” or “old” European Union countries; however, the exceptions of Ireland and Luxembourg (as with previous analyses using the linear ordering method and cluster analysis) is also shown.
6. Discussion
The analysis of the dynamics of the SDG10 indicators at the aggregated EU27 level emphasizes that between 2010 and 2019 the European Union was unable to reduce inequalities in all aspects analyzed. Although in the medium term, essential progress has been made with respect to the indicator measuring the reduction in disparities in household disposable income per capita, the indicator of the citizenship gap for early leavers from education and learning, or the indicator of the citizenship gap for the NEET rate, within-country inequalities persist. The analysis of three within-country inequalities informs that from 2010–2015 the disparities in the EU27 as a whole increased but there was a reduction observed from 2016–2019, but in 2019 the level of the three SDG10 indicators analyzed was generally higher than in 2010. In 2019, in comparison to 2010, the within-country inequalities slightly increased on average. The analysis of SDG10 indicators suggests the maintenance or even deepening of poverty in the EU. Despite this, some countries were able to reduce the inequalities; however, some of them worsened their position. The extended analysis provided by means of the use of selected socioeconomic indicators shows that the EU27 as a whole increased the share of social spending as a percentage of total spending over 2010–2019, but the size of the increase differs regardless of the group of countries and their structural characteristics.
The applied multivariate analysis, which is cluster analysis, supported by the use of the linear ordering method, provides important insights. The assessment of the (dis)similarities of the countries with respect to the chosen set of socioeconomic variables indicates that Spain, Romania, and Bulgaria maintain their position and are included in the most different group of countries in comparison to the rest of the EU. Such distinctiveness remains regardless of the analyzed year or the set of inputted variables. Contrary to these countries, there is a group of countries that are characterized by a low level of inequalities. For example, a relatively low poverty gap was observed in Czechia, the Netherlands, and Finland. Moreover, the use of an ordering method supports the insights obtained in cluster analysis. The ordering method emphasizes the high position of Sweden and Czechia as countries with good performance of individual country-level indicators, while cluster analysis allows inputting them into one cluster.
The analyses presented in this study contribute to the conclusion that, despite cohesion policy, inequalities, especially within-country inequalities, remain in the EU and there are persistent disparities. Furthermore, the presented values for the Gini coefficient illustrate that between 2010 and 2019 the income inequalities measured by this indicator decreased only in the case of 15 countries, but the size of the largest reduction (by 3.1 units in Slovakia) was nearly two times lower than the largest size of its increase (by 7.6 units in Bulgaria).
It is worth emphasizing that the cluster analysis based on the extended list of indicators highlights an important conclusion. The cluster for which the intra-cluster average for the income distribution variable was the lowest among the extracted countries, at the same time, had the highest intra-cluster average for spending on social protection, regardless of the year analyzed. The reverse also occurred—the cluster for which the average for income distribution was the highest, at the same time, was the cluster for which the average for social protection spending as a share of GDP was the lowest. This insight emphasizes the role of social policy in mitigating and reducing inequalities, especially within-country inequalities. The aforementioned relationship is also visible in correlation matrices for all datasets (see
Table A3 and
Table A4 in
Appendix A). For all of the EU27 countries, Pearson’s correlation coefficient between variables
and
is negative. In 2010 it is computed to be equal to −0.36 and in 2019 its value is −0.26. The correlation matrices also confirm the positive relationship between the old-age dependency ratio and social protection spending and between the young-age dependency ratio and social protection spending. The importance of the Agenda and SDG10 has increased in the context of the COVID-19 pandemic. This is because the pandemic has affected social and economic dimensions of countries all over the world.
The literature review did not provide similar studies that analyzed the performance of SDG10. However, in the context of implementing the 2030 Agenda, the existing literature leads to the same conclusion as expressed in this paper about the need for political and government support to successfully achieve the goals of the Agenda. This has recently been emphasized in the context of the crisis caused by the COVID-19 external shock. The pandemic has maintained or even deepened inequalities, mainly income disparities, both among and within countries, and made a few groups of people more vulnerable to the economic consequences of the crisis.
The results of the study are valuable and may support further research and further debates surrounding the role of social protection policies and sources of financial activities in order to progressively achieve greater equality.
7. Conclusions
This paper aims to analyze the progress of the EU27 with regard to SDG10 (which is assigned to reduce inequalities between and within countries). In order to achieve that goal, two studies are proposed. The first study is based on an analysis of the dynamics of SDG indicators for the EU27, while the second - on multivariate analysis that makes it possible to classify European Union countries from the point of view of their (dis)similarities with respect to a wider set of socioeconomic indicators. As a result, the multivariate analyses (i.e., cluster analysis and linear ordering method) are based on a set of variables including selected SDG10 indicators and selected socioeconomic variables that may affect the reduction of inequalities. The timeframe of the analyses, due to data availability, spans 2010 to 2019. All considered SDG indicators and analyzed socioeconomic variables derive from Eurostat.
The dynamics of the SDG10 indicators for the EU27 emphasize that between 2010 and 2019 the inequalities within countries slightly increased. The analysis implies that over the medium term (i.e., over the period 2010–2019) the EU27 was able to make progress in reducing inequalities among countries, but the income inequalities within countries persist or have even deepened. The insights from multivariate statistical methods emphasize the disparities between a group of countries (including Spain, Bulgaria, and Romania) and the rest of the EU countries in both analyzed years (i.e., in 2010 and 2019), regardless of the set of variables applied in analyses. This outcome seems to be robust, considering the methodology utilized. Furthermore, cluster analysis, as well as the PCA, points out the division of the EU27 into Western and Eastern countries as well as “old” and “new” EU member states. It implies that although the EU has an advanced cohesion policy, income inequalities and social exclusion persist in the EU. Another important insight from cluster analysis concerns the role of expenditure on social protection. As obtained, a cluster for which the intra-cluster average for income distribution is the lowest among separated clusters in the analyzed year, at the same time, is a cluster for which the intra-cluster average for social protection expenditure is the highest. The reverse is also confirmed. This observation emphasizes the potential role of social spending in mitigating inequalities. Moreover, the role of demography, especially aging, is emphasized in this study as being a factor affecting inequalities due to the advanced process of aging in Europe.
A few limitations should be emphasized. For example, the study is restricted by data availability. The lack of data, especially on SDG10 indicators addressing the citizenship gap at a country-specific level, determines a set of variables included in analyses and reduces their important impact on outcomes. As a result, the wider among- and within-country comparisons are obstructed. Moreover, due to collinearity, a large set of SDG10 indicators was excluded from multivariate analyses. Taking into account the results, there is a need for public policies to strengthen actions to achieve SDG10. The recognized inequalities harm sustainable development and impact the quality of life, mainly of the most vulnerable groups, including the old, the disabled, the unemployed, or migrants. The policies should encourage equality and eliminate disparities related to income, education level, gender, age, country of origin, and many other aspects.
The approaches that were used in the paper identified the group of countries that differ in the EU, emphasizing the division into “old” and “new” EU Member States. It is a crucial observation and a challenge for the EU as a whole because the inequalities were maintained over the 2010–2019 period. It shows that the cohesion policy is not sufficient and requires additional activities to help eliminate the disparities. Taking into account the analyzed data, goals, indicators, time sample, and results of the multivariate analyses, a few potential directions of the development of those policies can be outlined. These directions may take into account aspects that involve demographic changes, environmental changes, and globalization. An important point is related to the challenges created by the COVID-19 pandemic and its economic, social, and health consequences. The crisis revealed the need for governments to work to overcome the socioeconomic effects of the downturn, especially in terms of active and adequate social policies. Moreover, as emphasized, one factor that impacts the increase in the inequalities is the aging of society, which affects all EU countries. It seems that an appropriate social policy (mainly social security system, pension system, health care, long-term care) could effectively support the cohesion policy and, as a consequence, contribute to the more persistent reduction of inequalities. That policy could be conducted at the national level while also considering the common European social policy aspect. As presented in the study, the external shock, in the form of the pandemic, hindered the progress in reducing inequalities among and within EU countries, not only in terms of SDG10 but also the 2030 Agenda as a whole, i.e., through the scale of the interactions and the impact of SDG10 on the other SDGs.
As emphasized, the results of this study may contribute to debates surrounding the actions taken by policymakers to strengthen the progress towards SDG10. Mainly, there is a need for effective country-specific policies that could affect the areas responsible for building resilient societies and achieving sustainable development and the social inclusion of all. These debates should also focus on financing such policies and searching for more sustainable and efficient sources of funds. The study may support and stimulate further research because of the growing importance of the 2030 Agenda in reducing inequalities and the growing threat of escalation of poverty and income inequalities of many vulnerable groups of people. The results obtained in this study are valuable, especially in the context of the role of the 2030 Agenda in reducing inequalities caused by the COVID-19 pandemic.