Immigrant workers earn 29% less than people born in Spain

In a context in which population growth in most advanced economies will depend almost exclusively on immigration, the topic of this article is clearly timely and relevant. Having detailed information on the performance of immigrants in the labour market of the host country makes it possible to identify the most appropriate policies to improve their labour integration and, therefore, their quality of life.

From this perspective, the article makes a significant contribution in that it uses a similar methodological approach and highly detailed statistical information to analyse wage differences between natives and immigrants in a large sample of countries with very different backgrounds in terms of migration. The results obtained are not particularly novel in the context of the literature on the subject: immigrants earn less than natives for performing similar jobs. This wage gap narrows (but does not disappear) when the effect of different factors related to both personal characteristics and job characteristics is taken into account.

The article is basically descriptive and, therefore, the authors do not carry out a detailed analysis of the different mechanisms that explain these wage differences (nor do they explore other well-known results such as the double penalty for women), although they do point to some factors for which there is also ample evidence for most of the countries analysed (including Spain). For example, the literature has pointed to the imperfect transferability of human capital acquired in the country of origin and its impact on occupational mobility as one of the factors limiting the economic progress and wage assimilation of immigrants. Specifically, the mismatch between the skills and competences developed in the country of origin and those required in the destination country results in an initial loss in the occupational status of immigrants which, despite improving during their stay in the destination country thanks to improved language skills, on-the-job training, etc., does not fully compensate for the initial loss. The study does not allow us to conclude whether this segmented assimilation associated with limitations in access to better-paid jobs is due to discriminatory behaviour or other factors, but it is certainly an area of research that deserves to be explored in the future.

This study represents one of the most ambitious and robust approaches to date to analyse wage inequalities between immigrants and natives in developed countries. It is based on high-quality administrative microdata linking employers and employees for 13.5 million workers in nine countries, including Canada, the United States, Spain and several European economies. The methodology (country-specific regressions combined with meta-analysis) is statistically robust and allows us to distinguish between two fundamental causes of the gap: discrimination within the same job (within-job inequality) and segregation in access to better-paid jobs (between-job sorting). The central finding is that three-quarters of the wage gap is due to the latter, which is consistent with previous literature, but its comparative and systematic quantification is a real novelty of the article.

However, it should be noted that, although the design is rigorous, there are some limitations: in countries such as Spain, the available data do not allow a distinction to be made between first- and second-generation immigrants, which prevents intergenerational mobility from being studied adequately. Furthermore, differences within the same job are not fully explained, so it is possible that unobservable factors such as informal networks or institutional biases may also be influencing the results.

The Spanish case is particularly worrying. Spain has the highest overall wage gap in the entire study (29.3%) and one of the highest even for the same occupation and employer (7%). This highlights the existence of structural barriers to labour integration, even for workers who have already entered the formal market. Public policy in Spain should focus on: (i) improving the effective recognition of foreign qualifications; (ii) strengthening retraining programmes and access to labour networks; (iii) assessing possible biases in recruitment and promotion processes in large and medium-sized companies; and (iv) adapting active employment policies to the diversity of migration trajectories. Ignoring these mechanisms perpetuates inequalities and wastes skilled talent.