Inequality of Opportunity and Education - What It Is and How It Is Measured

Given my life experience and my interest in several areas of knowledge, one of the most important topics for me is education. Education has given me the vast majority of the things I value in life, both material and immaterial. And I have never been the perfect student (anyone who has known me for a long time knows this), nor have I had the privilege of attending private or highly prestigious institutions that opened up major academic and professional opportunities for me. I simply did what I could with the cards I had, and, more or less, things turned out well. At least well enough to receive awards, scholarships, and study at universities that are highly regarded around the world. I do not mention this as an exercise in arrogance, but because my own trajectory has led me to think a great deal about the role education plays in expanding or limiting a person’s opportunities. And, like me, thousands of students try to do everything they can to achieve their goals.

I was born in a country where access to education is much more limited, and where not everyone can move forward with the same tools. For many students, studying is not only a matter of talent or effort: it also depends on the material conditions of their family, the need to contribute economically at home, and the real possibility of imagining and pursuing ambitious aspirations. When I arrived in Spain, I discovered an education system that, despite its problems, offered me more opportunities than I had known until then. I felt that, with willpower and effort, I could go further, although always within certain limits and conditioned by several factors.

However, one of the most revealing experiences for me was also leaving the Spanish system and getting to know other education systems. That contrast allowed me to better appreciate both the strengths and weaknesses of our own. It also helped me think more deeply about what education really is, what role it plays in society, and what obstacles students encounter throughout their trajectories. Although education research often has a pedagogical dimension, my training as an economist leads me to be especially interested in its economic and life consequences. In other words, I approach it as a topic in economics. From that perspective, the issue that concerns me most is inequality of opportunity in education, especially in the Spanish case.

Although I have tried to write about this topic on other occasions, until now, I had not managed to find a framework for discussion that was clear, interesting, and robust enough to organise my ideas while also inviting others to think about and debate them. For that reason, this first article will be an accessible introduction to some fundamental questions about inequality of opportunity. The aim is to build a common foundation from which, later on, we can develop new ideas, refine previous intuitions, and discuss possible solutions. To do this, it is worth beginning with a basic question: what exactly do we mean by “inequality of opportunity”? From there, I will try to explain in a simple way how this phenomenon is studied in academia, what methods are usually used to measure it, and what some of the most relevant debates around it are.

In the current literature, inequality of opportunity is usually defined as the part of total inequality in outcomes that can be attributed to circumstances that were not chosen. In other words, we do not understand inequality of opportunity as the simple fact that two people end up obtaining different outcomes, but rather as the part of those differences that cannot reasonably be attributed to their individual decisions or efforts. This way of understanding the problem is closely associated with the tradition developed by Roemer and systematised, among others, by Roemer and Trannoy. However, the debate has not always been framed in this way: Dworkin defended an idea of equality of resources, Arneson spoke of “equality of opportunity for welfare,” and Fleurbaey and Maniquet focused on compensation for disadvantages for which the individual is not responsible. What matters about this evolution is that it allows us to move from a philosophical discussion about what should be equalised to a more concrete empirical question: what part of observed inequality can be attributed to circumstances that people did not choose?

One quantitative way of approaching inequality of opportunity consists of comparing groups of individuals defined only by their circumstances. It can also be estimated by calculating differences in the outcomes predicted by a model that uses those circumstances as explanatory variables. Clearly, this is not easy, and there are usually three main reasons for this.

1. To make a realistic or precise comparison, one would have to take into account all the relevant circumstances of individuals, something that is not possible in practice. For this reason, statistical or empirical studies tend to underestimate true inequality of opportunity: they can only measure the part that the available data allow us to observe.

   
   

2. The results can vary depending on the specification of the model, the variables included, and the way in which different groups of individuals are divided. Therefore, estimates must be interpreted with caution: they are not a perfect photograph of reality, but an approximation conditioned by the data and by the researcher’s methodological decisions.

   
   

3. Inequality of opportunity is not something that occurs at a specific moment in our lives, but rather a phenomenon that unfolds throughout the life cycle. However, we often only have annual, monthly, or point-in-time data. For example, annual income is commonly used, but this is not equivalent to measuring a person’s permanent income over their entire life. This can make it difficult to estimate equality of opportunity accurately, because the circumstances that affect a person can accumulate and change in importance over time.

Figure 1. Intuitive graph of the measurement problems of the inequality of opportunities in the empirical literature.

In addition, there are different families of indicators for measuring inequality, and the choice of one or another can affect the results obtained. For this reason, even when we share a general definition, statistical decisions remain important.

This allows us to understand a central idea that is worth taking away from this discussion. The definition of inequality of opportunity has evolved, and today we have a definition that is relatively intuitive and useful for empirical study; that is, for working with data and obtaining evidence-based conclusions. Nevertheless, the fact that this definition is useful does not mean that the boundary between effort, individual decisions, and unchosen circumstances is completely clear. On the contrary, many conceptual and methodological details arise when one tries to study this phenomenon rigorously.

All of this shows that we are dealing with a complex topic, not only from an argumentative point of view, but also from a statistical and formal one. Since I will be writing about this issue recurrently, not all articles will have the same purpose: some will be more expository, others more argumentative, and others will be devoted to reviewing concrete evidence. The intention is not to close the debate, but to gradually build a common framework that allows us to think about it better, especially when we discuss the Spanish education system.

Once the general idea of inequality of opportunity and some of the basic difficulties involved in measuring it have been introduced, the natural next step is to review what we know about its mechanisms of transmission. First, it is worth understanding how inequalities are transmitted and what implications they have in people’s lives. Then, we can look at some comparative evidence across countries and examine Spain in greater detail, since it is the case that interests me most. Only with that foundation will we be able to better understand how education and inequality of opportunity are related, what the main problems facing Spain are, and what possible solutions are worth discussing.

References

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• Arneson, R. J. (1989). Equality and equal opportunity for welfare. Philosophical Studies, 56(1), 77–93. https://doi.org/10.1007/BF00646210

  
  

• Bourguignon, F., Ferreira, F. H. G., & Menéndez, M. (2007). Inequality of opportunity in Brazil. Review of Income and Wealth, 53(4), 585–618. https://doi.org/10.1111/j.1475-4991.2007.00247.x

  
  

• Brunori, P., Peragine, V., & Serlenga, L. (2018). Upward and downward bias when measuring inequality of opportunity. IZA Discussion Paper No. 11405. https://www.iza.org/publications/dp/11405/upward-and-downward-bias-when-measuring-inequality-of-opportunity

  
  

• Cabrera, L., Marrero, G. A., Rodríguez, J. G., & Salas-Rojo, P. (2021). Inequality of opportunity in Spain: New insights from new data. Hacienda Pública Española / Review of Public Economics, 237(2), 153–185. https://doi.org/10.7866/HPE-RPE.21.2.6

  
  

• Calo-Blanco, A., & Villar, A. (2010). Quality of education and equality of opportunity in Spain: Lessons from PISA. Fundación BBVA, Documento de Trabajo 6/2010.

  
  

• Dworkin, R. (1981). What is equality? Part 2: Equality of resources. Philosophy & Public Affairs, 10(4), 283–345. https://www.jstor.org/stable/2265047

  
  

• Ferreira, F. H. G., & Gignoux, J. (2011). The measurement of inequality of opportunity: Theory and an application to Latin America. Review of Income and Wealth, 57(4), 622–657. https://doi.org/10.1111/j.1475-4991.2011.00467.x

  
  

• Fleurbaey, M., & Maniquet, F. (2006). Compensation and responsibility. HAL Open Science. https://shs.hal.science/halshs-00121367

  
  

• Marrero, G. A., Palomino, J. C., & Sicilia, G. (2024). Inequality of opportunity in educational achievement in Western Europe: Contributors and channels. The Journal of Economic Inequality, 22, 383–410. https://doi.org/10.1007/s10888-023-09595-5

  
  

• Paes de Barros, R., Ferreira, F. H. G., Molinas Vega, J. R., & Saavedra Chanduvi, J. (2009). Measuring inequality of opportunities in Latin America and the Caribbean. World Bank. https://doi.org/10.1596/978-0-8213-7745-1

  
  

• Roemer, J. E. (1998). Equality of opportunity. Harvard University Press.

  
  

• Roemer, J. E., & Trannoy, A. (2015). Equality of opportunity. En A. B. Atkinson & F. Bourguignon (Eds.), Handbook of Income Distribution (Vol. 2A, pp. 217–300). Elsevier. https://doi.org/10.1016/B978-0-444-59428-0.00005-9

  
  

• Sicilia, G., Marrero, G. A., & Palomino, J. C. (2022). Inequality of opportunity in educational performance in Spain and Europe: The role of expectations, reading skills and repetition as determinants of inequalities. “la Caixa” Foundation, The Social Observatory.

  
  

• Suárez Álvarez, A., & López Menéndez, A. J. (2025). The role of family background and education in shaping inequalities: Evidence from the Spanish regions. Social Policy and Society, 24(2), 355–372. https://doi.org/10.1017/S1474746423000179