The rich marry the rich: How love perpetuates inequality – EL PAÍS English

Socioeconomic Homogamy and its Impact on Sustainable Development Goals in Spain

Introduction: A Challenge to SDG 10 (Reduced Inequalities)

Recent analysis of socioeconomic data in Spain reveals that partner selection is heavily influenced by economic status, a phenomenon known as homogamy. This trend of individuals partnering with those of similar income and wealth poses a significant structural barrier to achieving Sustainable Development Goal 10 (Reduced Inequalities). The pattern is most pronounced among the wealthiest segment of the population, where it perpetuates and amplifies economic disparities, undermining efforts for a more equitable society.

Key Findings on Partnership Patterns and Economic Segregation

Statistical Evidence of Assortative Mating

A study conducted by Silvia de Poli, utilizing microdata from the Spanish Ministry of Finance and the National Institute of Statistics (INE), provides quantitative evidence of this social stratification. The findings indicate a significant deviation from random partner selection, with profound implications for wealth distribution and social mobility.

• Individuals in the top 10% of earners are 3.1 times more likely to form a couple with each other than would be expected by chance.
• Conversely, a man from the highest income decile is five times less likely to partner with a woman from a lower-middle income bracket compared to a random scenario.
• When analyzing wealth, a more stable indicator than income, the pattern of homogamy is consistent across all economic strata, with the wealthiest pairing with the wealthiest and the poorest with the poorest.
• Among couples in the top income decile, 33% belong to the same income group, double the average rate of 16% observed across the general population.

The Role of Education in Perpetuating Inequality

The research identifies educational attainment as a primary mechanism driving economic homogamy, directly impacting SDG 4 (Quality Education) by highlighting how educational stratification translates into lifelong economic inequality.

• A strong correlation exists between educational level and income, meaning that educational homogamy often leads to income homogamy.
• Couples in the highest income brackets exhibit the smallest educational differences between partners.
• At the top of the economic ladder, partners almost invariably share similar, high levels of educational attainment, whereas greater educational diversity is found among couples in lower-income groups.

Simulating the Impact on SDG 1 and SDG 10

Modeling Alternative Scenarios for Partnership Formation

To quantify the effect of homogamy on inequality, a simulation was conducted comparing Spain’s current reality to hypothetical scenarios. This modeling underscores how social norms directly obstruct progress towards SDG 1 (No Poverty) and SDG 10.

1. Random Scenario: Couples form randomly, without regard to economic status. In this model, economic inequality would significantly decrease.
2. Perfect Homogamy Scenario: The richest individuals partner exclusively with the richest, and the poorest with the poorest. Spain’s current situation trends closely towards this model.
3. Complete Heterogamy Scenario: Individuals from the top of the economic scale partner with those from the bottom.

The simulation concluded that under a random partnering scenario, the bottom 80% of income earners would improve their economic standing. This demonstrates that selective partnering actively concentrates wealth among the top 20%, hindering poverty reduction and widening the inequality gap.

Implications for Sustainable Development and Public Policy

Concentration of Wealth and Barriers to Social Mobility

The perpetuation of homogamy creates formidable economic powerhouses at the top of the social ladder, challenging the principles of SDG 8 (Decent Work and Economic Growth) and SDG 16 (Peace, Justice and Strong Institutions).

• Couples in the wealthiest 10% possess, on average, 12 times the income and 42 times the net worth of couples in the lowest decile.
• This concentration of resources ensures that children from these unions inherit significant advantages, limiting opportunities for those with fewer resources and weakening the “social elevator.”
• Social structures, including exclusive networks and residential segregation, create barriers that make it difficult for individuals from different socioeconomic strata to interact, further entrenching class divisions.

The Limits of Current Policy and the Path Forward

While public policies such as taxation can partially mitigate the impact of homogamy on inequality, the study suggests they are insufficient to counteract the systemic accumulation of wealth driven by selective partnering. Achieving the Sustainable Development Goals requires a more robust policy framework.

• Strengthening Institutions (SDG 16): Policies must be designed to more effectively redistribute wealth and challenge the structural drivers of inequality.
• Promoting Gender Equality (SDG 5): Although the study was limited to heterosexual couples, understanding and addressing how these patterns affect women’s economic empowerment is crucial for equitable development.
• Ensuring Inclusive Education (SDG 4): Policies aimed at desegregating educational institutions and ensuring equal access to quality education for all can help break the cycle of homogamy and inequality.

Analysis of the Article in Relation to Sustainable Development Goals

1. Which SDGs are addressed or connected to the issues highlighted in the article?

1. SDG 10: Reduced Inequalities
   • The article’s central theme is the perpetuation of economic inequality in Spain through the practice of homogamy, where individuals marry within their own socioeconomic class. It directly addresses the widening gap between the rich and the poor, stating that this trend “contributes to perpetuating income inequality.” The analysis of income and wealth distribution across different deciles is a core component of SDG 10.
2. SDG 5: Gender Equality
   • Although the primary focus is on class, the analysis is conducted on heterosexual couples, and the data often distinguishes between men and women. For instance, it notes, “Men and women in the top 10% of earners are 3.1 times more likely to marry each other.” The study’s limitation to heterosexual couples due to data availability also highlights a dimension of gender and social data collection. The economic structures formed by couples have direct implications for the economic empowerment and opportunities available to women within those partnerships and in society at large.
3. SDG 4: Quality Education
   • The article explicitly links educational attainment to both income levels and partner selection. It states, “one of the best [measurable factors] for exploring the origins of socioeconomic segregation is education.” It further explains that at the top of the economic ladder, “partners almost always share a similar, generally higher, levels of educational attainment,” demonstrating how educational background is a key mechanism in the social sorting that leads to economic inequality.
4. SDG 1: No Poverty
   • The article connects the concentration of wealth at the top to the economic situation of those at the bottom. It explains that if marriages were random, “couples in the lowest 80% of income earners — especially those at the bottom of the scale — would be better positioned.” This implies that the current system of selective marriage exacerbates the economic challenges faced by the poorest segments of the population, making it harder to reduce poverty.

2. What specific targets under those SDGs can be identified based on the article’s content?

1. Under SDG 10 (Reduced Inequalities):
   • Target 10.1: By 2030, progressively achieve and sustain income growth of the bottom 40 per cent of the population at a rate higher than the national average. The article’s simulation of random marriages shows that such a scenario would improve the economic standing of the “lowest 80% of income earners,” directly relating to the goal of improving the economic situation of the bottom percentiles of the population.
   • Target 10.2: By 2030, empower and promote the social, economic and political inclusion of all, irrespective of… economic or other status. The article describes how social structures create “exclusive spaces where only the privileged have access and can meet each other,” which is a barrier to social and economic inclusion and mobility.
   • Target 10.3: Ensure equal opportunity and reduce inequalities of outcome. The article highlights how homogamy ensures that children of wealthy couples “are born with above-average wealth,” perpetuating a cycle of advantage and reducing equal opportunity for those from lower-income backgrounds. It also notes that existing public policies are “unable to halt the gradual accumulation of wealth resulting from selective marriages.”
2. Under SDG 4 (Quality Education):
   • Target 4.5: By 2030, eliminate gender disparities in education and ensure equal access to all levels of education… for the vulnerable. The article shows a strong link between socioeconomic status and educational pairing (“the higher the economic level, the more similar the couples’ educational paths are”). This suggests that educational opportunities and outcomes are stratified by economic class, which is a form of inequality in access that this target aims to address.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

1. Indicators for SDG 10 (Reduced Inequalities):
   • Income and wealth distribution by decile: The article is built around data that divides the population into 10 economic groups (deciles). It provides specific figures, such as couples in the top 10% holding “12 times the income and 42 times the net worth of those in the lowest decile.” This decile-based analysis is a direct way to measure income inequality.
   • Rate of assortative mating (homogamy): The study quantifies the likelihood of people marrying within their own economic group. The finding that “Men and women in the top 10% of earners are 3.1 times more likely to marry each other than if everything were left to chance” serves as a specific indicator of social and economic segregation.
   • Percentage of couples within the same income group: The article provides a clear metric: “in the top decile the rate [of belonging to the same income group] doubles to 33%.” This percentage can be tracked over time to measure changes in social mobility and inequality.
2. Indicators for SDG 4 (Quality Education):
   • Educational gap within couples by income level: The research mentioned in the article “observed the educational gap within each union.” Finding that couples in the highest income brackets have the “least educational differences” provides a measurable indicator of how education and economic status are intertwined. Tracking this gap could measure progress in decoupling educational outcomes from socioeconomic background.

4. Summary Table of SDGs, Targets, and Indicators

Source: english.elpais.com