The impact of socioeconomic status on academic performance in Spain is significant and similar to that found in neighbouring countries. In Spain, inequalities related to socioeconomic differences appear before students reach 10 years of age and do not decline subsequently. The economic crisis has slightly increased the impact of inequalities caused by socioeconomic factors. The main guiding principles for policies aimed at correcting these inequalities include early intervention, the use of targeted aid and reducing segregation at schools.

Educational inequalities can be associated with diverse factors, for example gender, place of origin and student disability. This article attempts to provide answers to the following three questions: 1) What impact does socioeconomic status have on the performance of Spanish students?; 2) Does this impact differ from that observed in neighbouring countries?; 3) How has educational inequality related to socioeconomic differences evolved recently in the Spanish education system? The answers will help to establish principles that can help guide the design of effective education policies.

Students' socioeconomic status conditions their academic performance. This has been widely verified by empirical evidence. It is also known that the effects of socioeconomic inequalities can be transmitted through diverse mechanisms, such as, for example, differences in parental expectations, the availability of educational resources in the home, or “peer effects”, i.e. the influence of the socioeconomic status of other students in the school.

Students' socioeconomic status is a broader concept than just household income level. It includes the latter but also incorporates other dimensions, such as parents' educational attainment levels and their occupational and employment situation. Hence, in practice, this concept is examined through different measures (parents' educational attainment and income level, books in the home, etc.). Each of these variables has strong and weak points when describing socioeconomic status. This article uses the index of economic, social and cultural status (ESCS) employed by the OECD's PISA (Programme for International Student Assessment) programme, which combines several dimensions (parents' educational attainment, employment situation and household possessions) to describe the socioeconomic status of students' households.

Household socioeconomic status is certainly one of the main determinants of Spanish students' performance. This causal relationship has been clearly established, independent of the methodology used, the definition of socioeconomic status and the databases employed (general diagnostic assessments, regional evaluations, and international programmes such as PISA). For example, at the age of 15, which is nearly at the end of compulsory education, comparison of the scores obtained in scientific competencies as measured by PISA 2015 by Spanish students from homes of a higher socioeconomic status (the top 25% or highest quartile) with that of students from homes with the lowest socioeconomic status (the bottom 25% or lowest quartile), shows a gap of 82 points (OECD, 2016a). The PISA scale ranges from 0 to 1000 points and such a gap is equivalent to approximately two years of education.

Given these findings, it is not surprising that these socioeconomic inequalities are also reflected in other educational results closely related to academic performance. Thus, Spanish students with a lower socioeconomic status (the lowest 25%) face a greater risk of repeating a year: in 2015, some 53.5% of students in this quartile had repeated a year before reaching 15 years of age, in comparison to only 8.7% of students from households in the highest socioeconomic quartile. In addition, findings indicate that repeating a year has continuing negative effects on students' performance, amplifying the impact of low socioeconomic status (Choi et al., 2017). Other studies (such as Choi and Calero, 2013) reveal that the socioeconomic status constitutes one of the main determinants of the risk of early school leaving – i.e., not completing upper secondary education. With an early school leaving rate of nearly 18% in 2017, this issue is probably one of the greatest challenges the Spanish education system faces.

Many studies have shown that in the Spanish case, the effect of socioeconomic inequalities is also transmitted through the social composition of schools. In Spain, both independent and publicly-subsidized private schools tend to educate students from families with a higher socioeconomic status than the families of students at public schools. In analysing the average results of these schools, it can be seen that students from private schools score better on PISA tests than those from public schools (indigo bars in figure 1). However, as can be seen in figure 1, this gap in performance is reduced (magenta bars) once the effect of students' socioeconomic status is taken into account, and it disappears if the effect of the differing socioeconomic composition of the student body in function of the type of school (public or private) is also taken into account (blue bars). In other words, analysis shows that the quality of public and private schools is similar, and it is the socioeconomic composition of the student body that is the main determinant of the differences found. In fact, academic achievement in public schools is slightly higher than in private schools if the effect of socioeconomic status is controlled for.
 

A final relevant factor on this point in terms of the design of educational reforms is the identification of the point at which the educational inequalities that distinguish students from different socioeconomic backgrounds are generated. Obtaining evidence for this requires the use of comparative data over time that will enable the tracking of students over long periods. Although this type of information is limited for the Spanish case, linking data from the PIRLS (Progress in International Reading Literacy Study) with PISA data makes it possible to establish that educational inequalities in Spain linked to socioeconomic differences appear before students reach the age of 10 years, i.e., during primary education or even earlier. The results of reading tests carried out at 10 years of age reveal considerable differences according to family socioeconomic status. This inequality appears early in the life of children and remains or is exacerbated during secondary education (Choi and Jerrim, 2016).

International evaluations are useful tools for comparing educational inequalities with respect to neighbouring countries.

Figure 2a measures the difference in academic results between two students that differ by one unit on PISA's ESCS index. This difference, referred to as “the slope of the socioeconomic gradient”, is expressed in points on the PISA scale and provides a measure in absolute terms of the importance of socioeconomic status on educational performance. Taking figure 2a as an example, it can be seen that the distance between the scores of Danish students from the highest and lowest socioeconomic quartiles is approximately 34 points, while in Spain it is 27.
 

Figure 2b shows what proportion of total inequality between the results of students can be attributed to prior inequalities in family socioeconomic status. This is expressed as the percentage of variance (the difference between the best and worst results in a country) that is explained by socioeconomic status and gives a measure of the importance of said status in explaining the differences found in academic results. In other words, it reflects the importance that the socioeconomic gradient has in explaining educational results.

In some countries the distance between the results of excellent and poor students is small when considering their socioeconomic backgrounds, while in others the differences are greater. Spain is found among the former group of countries: the distance in terms of the scores between excellent and poor students is small. In other words, results in Spain do not vary greatly (or, alternatively, it can be said that their distribution is compact). Figure 2b shows the importance, in relative terms, of socioeconomic status in explaining inequalities in results within each country. As can be seen, the value for Spain stands at around 13%, slightly above the average for OECD countries.
 

Continuing with this example: Is the effect of socioeconomic inequalities greater in Spain than in Denmark? In absolute terms, no: the slope of the socioeconomic gradient is 7 points greater in Denmark, to be exact (figure 2a). However, if the focus is placed on the weight of socioeconomic status to explain total educational inequalities (figure 2b), the answer is yes: socioeconomic status is a stronger determinant of educational performance in Spain than in Denmark (figure 2b). The information provided by figures 2a and 2b enables contextualisation of the aggregate effect of socioeconomic status on the overall population.

However, what happens at the extremes? In other words, how do students with the highest and lowest socioeconomic statuses in Spain perform? Figure 3 shows that, in Spain, the gap in performance between students with the highest and lowest socioeconomic statuses (the highest and lowest quartiles) is similar to the OECD average.
 

To a great extent, the moderate size of this gap is due to the high percentage of resilient students in the Spanish economic system, which can be seen represented in figure 4. Resilient students are defined as those who come from homes of a low socioeconomic status and that, nevertheless, obtain high educational results.

However, the results shown in figures 2 and 3 need to be qualified: in Spain, belonging to a home in the lowest socioeconomic quartile multiplies the risk of obtaining very poor academic results by six, while for the overall OECD, this risk increases only 4.41 times. The combination of prior results means it can be stated that, comparatively, in Spain:

a) A significant proportion of students with a low socioeconomic status obtain high results;

b) the majority of students with a low socioeconomic status, however, have low scores; and

c) it is unusual for students from households with a high socioeconomic status to score low on competencies.
 

The results for students of 15 years of age at the aggregate level seem to indicate a slight increase in the slope of the socioeconomic gradient between 2006 and 2015 (that is, the difference in the performance of students from different socioeconomic backgrounds increased slightly). However, the importance of socioeconomic status as an explanatory factor for inequality in educational results remained constant (OECD, 2016a).

The period analysed is marked by the deep economic crisis that began in 2008, and the subsequent recovery starting in 2013. In this sense, the economic crisis could affect levels of educational inequality in different ways, with two factors in particular standing out: first, the worsening of the employment situation among Spanish households and, secondly, the contraction of state budgets related to the welfare state and education.

Regarding the first of these factors, the destruction of employment and worsening of working conditions affected the performance of students from homes with the lowest socioeconomic statuses most severely. During the economic crisis these students saw their disadvantaged situation with respect to other students worsen (Guio et al., 2018). Regarding the second factor – cuts in state budgets – public spending on education dropped by 15% between 2009 and 2014.

However, one positive aspect of the economic crisis that can contribute to reducing educational inequalities related to socioeconomic differences, is that there has been a gradual decline in the rate of early school leaving – which is highest among students from lower socioeconomic backgrounds. This can be linked to less availability of low-skilled jobs for people with low educational attainment levels.

Certain of the main determinants of academic performance among Spanish students are related to socioeconomic factors: students from households better positioned on the social scale tend to obtain better educational results. Education is associated with many monetary and non-monetary benefits. As a result, considering that no one chooses the home in which they are born, and that education is one of the primary mechanisms of social mobility, the reduction of educational inequalities related to socioeconomic differences constitutes one of the necessary objectives for guaranteeing the principle of equal opportunities. Reducing educational inequalities between students and schools resulting from socioeconomic causes would contribute to improving the employability and productivity of society's future workers. Thus, for both reasons of equity and efficiency the introduction of policies aimed at correcting these inequalities is necessary. The evidence presented in this article suggests a series of guiding principles for designing said policies.

First, is the need to intervene early in the education system, as inequalities are generated during the first decade of students' lives. A promising policy in this direction would be increased participation by the public sector in early childhood education (0-3).

Second, is the usefulness of maintaining targeted aid, such as scholarships, for students from lower socioeconomic backgrounds, as it has been shown that such aid can reduce early disadvantages.

Third, it must be taken into account that essential educational decisions (such as how much and what to study) are impacted by the level of information households have, which is also closely related to socioeconomic level. As a result, it could be useful to explore the introduction of mechanisms that facilitate decision-making processes for households and for students. An example would be to strengthen academic guidance services.

Lastly, given the importance of “peer effects”, it is urgent to reduce the segregation of students in schools based on socioeconomic differences. The intensification of inspections for controlling schools' processes for selecting students would be useful in this regard. To conclude, it is necessary to adapt these policies to the heterogeneous realities existing within Spain.

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CHOI, Á; GIL, M; MEDIAVILLA, M.; and VALBUENA, J. (2017). The evolution of educational inequalities in Spain: Dynamic evidence from repeated cross-sections. Social Indicators Research, DOI: 10.1007/s11205-017-1701-6.

CHOI, Á. and JERRIM, J. (2016). The use (and misuse) of PISA in guiding policy reform: the case of Spain. Comparative Education, 52(2): 230-245.

GUIO, J.; CHOI, Á; and ESCARDÍBUL, J-O. (2018). Labor markets, academic performance and school dropout risk: evidence for Spain. International Journal of Manpower, 39(2): 301-318.

OCDE (2016a). PISA 2015 Results (Volume I): Excellence and Equity in Education. París: OECD.

OCDE (2016b). PISA 2015 Results (Volume II): Policies and Practices for Successful Schools. París: OECD.