In Spain, between the years 2000 and 2008, the rate of foreign pupils in schools rose from 2% to 10%. Foreign schoolchildren were concentrated mostly in publicly owned schools, causing a movement of native pupils from an advantaged socioeconomic background towards private or charter schools. This shift in enrolment preferences could erode social commitment to public education and hinder the integration process of new arrivals. 

Education drives growth and development. Investment in education yields benefits not only for the individual but also for society as a whole. Countries with a better educated population are more productive, have lower levels of crime and conflict, and register greater citizen participation (Moretti, 2005). In addition, in most countries it is observed that individuals with higher levels of education earn higher wages. 

It is precisely these social benefits that justify investment in public education. Furthermore, an accessible quality education system is a good tool for combating inequality and encouraging social mobility (Fernández and Rogerson, 2003). The latter characteristic of the education system acquires special relevance in the present context, in which countries with high welfare standards become receivers of large waves of migrants. 

Many families make the decision to move to another country in the hope that their children will receive a better education. For this reason it is important for the education system of host countries to be capable of integrating newcomers, thus fostering integration and social cohesion and reducing conflict. However, the mass arrival of immigrants in classrooms could bring about a flight of native children to private schools, which would erode the social commitment to quality public education (Coen-Pirani, 2011; Epple and Romano, 1996). 

Since the beginning of the 21st century, the system of compulsory education in Spain has been divided into two stages: primary education, which spans from age 6 to age 12; and secondary education, from age 12 to age 16. Two types of schools exist side by side in Spain: public, which take approximately 70% of the school population, and private (most of these charter schools), which take the rest of the pupils. Schooling is free in public sector schools, while the other sort charge fees that vary significantly from school to school. Private and charter schools often require considerable outlays by families, usually associated with complementary activities (OCU, 2012). 

In the first decade of the 21st century Spain experienced one of the largest migratory flows worldwide. Between 2000 and 2008, in full economic upswing, the working age population born abroad increased from 4% to 12%. This increase was also felt in the classrooms of schools providing primary and compulsory secondary education, where the percentage of foreign schoolchildren rose from 2% to 10% in the same period, from 97,549 to 525,481 pupils (graph 1). 

Although the private education system, including charter schools, is larger in Spain than in other developed countries (for example, the enrolment rate in private schools is 14% in the EU-28, but around 30% in Spain), immigrants were concentrated mainly in publicly owned schools. As can be seen in graph 2, in the late 1990s the percentage of foreign schoolchildren in both systems was very low (2.6% in public schools and 1.4% in private schools).

By 2008 the presence of foreign schoolchildren in public schools had reached 14% of the total, whereas in private schools it stood at less than half this figure: 6.45%. This gap persists to the present day. 

The information on the number of foreign children enrolled in schools gives a very accurate reflection of the presence of immigrants in an area. Traditionally, studies have used census data to measure the size of migratory waves. However, census data is subject to measurement errors and requires statistical refinement due to the difficulty of reflecting real-time changes. In contrast, school enrolment data affords a more accurate measure of the density of foreign pupils in schools.

Graph 3 plots the evolution of rates of foreign pupils in primary and secondary schools. In addition to the general trend caused by the economic situation, we can see how at first the rate grew faster in primary schools, which reflects the fact that the immigrants arriving in Spain were mostly young people with young children. A few years later, the rate of foreign pupils in secondary schools followed the same pattern. 

Several studies have shown that many native families respond to the mass influx of foreign pupils by taking their children to private schools or changing their place of residence in order to be able to access schools with a lower concentration of immigrants. This reaction is known in the literature as native flight (Coen-Pirani, 2011; Cascio and Lewis, 2012). In order to identify which families enrol their children in private or charter schools and which do so in public schools the authors analyse the families’ educational spending decisions using data from the Household Budget Survey for the period 2000-2015. 

Graph 4 presents the evolution of the enrolment rate of native pupils in private and charter schools, and shows a considerable increase in the period 2000-2008, coinciding with the rise in the immigrant population and also with a period of sharp growth in household income. It is im-portant to note that the increase in enrolment rates in private schools occurred first in primary education, in line with the greater initial impact of immigration in that educational bracket (graph 3). 
 

The geographical variation between autonomous communities of the concentration of foreign children in classrooms makes it possible to quantify its impact on families’ enrolment decisions. As is shown in graph 5, growth rates of the number of pupils were not homogeneous: between 1998 and 2018, the number of pupils diminished in four communities (Asturias, Extremadura, Castile and Leon, and Galicia), as the influx of foreign pupils was not sufficient to offset the decrease in the number of native pupils. In contrast, the number of schoolchildren remained constant in the Canary Islands and increased in all the other regions. The graph also shows an uneven increase in the growth rate of the number of foreign pupils between autonomous communities. This geographical variation enables us to identify the effect immigration has on the education system, isolating it from the business cycle and other factors. 

If we combine the data on geographical variation in foreign schoolchildren with the data on families’ decisions, we see that from 2000 to 2007 the rate of enrolment in private and charter schools rose by 12 percentage points among native families with a higher socioeconomic status. However, no changes are observed in the use of public schooling among less well-off families. This asymmetry in the response is known as cream skimming, and refers to wealthy families’ greater ability to react to changes in the school environment. 

In the period spanning from 2008 to 2015, the economic crisis reduced household income and deterred the arrival of immigrants. Both these factors helped to slow down enrolment rates in private schools. The drop in foreign schoolchildren is estimated to have caused a 0.8% reduction in the rate of enrolment in private and charter primary schools among families with high socioeconomic status, although the reduction for all families stood at almost 1.5%. 

In secondary education a similar pattern is observed. In the period from 2000 to 2007, the rate of foreign pupils rose by 8 percentage points, and native families with a high socioeconomic status responded by increasing the rate of enrolment in private and charter schools by 11 percentage points. However, during the period of economic crisis and reduction of migratory flows (from 2008 to 2015), the enrolment rate in private and charter schools fell by 2 percentage points among families as a whole. 

These results highlight the notable effect that the concentration of immigrants in classrooms has on families’ school choice. The magnitude of this effect is estimated at approximately half of that associated with changes in household income. 

The shift by native families towards private and charter schools could affect the quality of the public education system, as it implies less social and political interest in financing it. Tanaka, Farré and Ortega (2018) analyse the impact of immigration on public education from a political economy perspective. In this context, the tax burden and the allocation of public funds by legislators reflect the use of public education by those who voted for them. The arrival of immigrant families with less than average income and higher birth rates may lead some native voters to enrol their children at private and charter schools, and to cease to support public investment in education. 

The above results indicate that the influx of foreign schoolchildren in classrooms during the first decade of the 21st century coincided with a shift towards the private education system among wealthier native families. This shift may have discouraged increases in public expenditure on education. 

The long-term evolution of the public education system depends to a large extent on the economic and social integration of immigrant families. If the income levels, preferences for public education and birth rates of immigrant families converge towards those of native families, the quality of education in public schools and their use among native families will be restored. However, it must be stressed that social and economic assimilation processes are not automatic and should be actively encouraged through appropriate public policies. At the same time, the education system should play a fundamental role as a driving force for integration and social mobility. 
 

In this context, it is important to assess the impact that the economic crisis caused by the covid-19 pandemic may have on the education system. One of the most outstanding features of the current crisis is the fall in the employment level. According to our predictions, the drop in income as a result of job loss may lead many families to leave charter or private schools and choose to take their children to public schools. In the short term this might generate overcrowding and have a negative effect on the quality of the public education system. But it might also raise social support for spending on public education, which would have positive effects on the quality of public schooling in the mid term. 

CASCIO, E.U., and E.G. LEWIS (2012): «Cracks in the melting pot: immigration, school choice, and segregation», American Economic Journal: Economic Policy, 4(3). 

COEN-PIRANI, D. (2011): «Immigration and spending on public education: California, 1970– 2000», Journal of Public Economics, 95(11-12). 

EPPLE, D., and R.E. ROMANO (1996): «Ends against the middle: determining public service provision when there are private alternatives», Journal of Public Economics, 62(3). 

FARRÉ, L., F. ORTEGA and R. TANAKA (2018): «Immigration and the public-private school choice», Labour Economics.

FERNÁNDEZ, R., and R. ROGERSON (2003): «Equity and resources: an analysis of education finance systems», Journal of Political Economy, 111(4). 

MORETTI, E. (2005): «Social returns to human capital», NBER Reporter: Research Summary.
 
OCU (2012): «La creciente factura escolar», OCU-Compra maestra, 373. 

TANAKA, R., L. FARRÉ and F. ORTEGA (2018): «Immigration, assimilation, and the future of public education», European Journal of Political Economy, 52