Interaction between people of different ethnicities and languages in a country improves the provision of public goods such as health, Education and infrastructure. This is the conclusion of a study conducted by Joseph F. Gomes, researcher of the Navarra Center for International Development (NCID) of the Institute for Culture and Society of the University of Navarra; Klaus Desmet, researcher of Southern Methodist University (USA); and Ignacio Ortuño-Ortin, of the Carlos III University of Madrid.

The experts aimed to discover whether a nation's diversity has positive effects on public policies. They started from the hypothesis that the lack of agreements due to antagonism causes some countries to have more conflicts, less development and worse public goods. "Tensions can arise between different groups over the language to be used in the Education, the distribution of the network of roads or where to locate the most important hospitals," they indicate.

During the research they mapped the world's linguistic diversity by creating a global database showing the use of local languages at a scale of 5km2 in 223 countries.

Public policies to facilitate the contact

Two variables were focused on. The first is ethnolinguistic fragmentation, the antagonism an individual feels towards a compatriot of another ethnicity and language. The second is social learning, how interaction with members of the other ethnolinguistic group affects antagonism.

The study found that prejudice decreases when these groups interact in their day-to-day lives: "Diversity is sometimes viewed more negatively in relatively homogeneous localities than in those with high diversity".

As an example, they cite the case of Brexit, which responds to concerns about regaining control over the flow of migrants in the United Kingdom. "The perception that there is a lot of diversity is especially strong in areas with fewer foreign residents and much lower in cosmopolitan London," they state.

The researchers point out that two ways in which governments facilitate contact among a country's diverse groups are public housing programs - to make a more equal distribution of diversity among different neighborhoods - or the integration of different groups in schools to avoid segregation. "Naturally, they are not without controversy, as they reduce individual freedom of choice to achieve socially desirable outcomes," they point out. 

• See research 'The Geography of Linguistic Diversity and the Provision of Public Goods'.