Society can end up being polarised into two groups of thinking and physically segregated according to one socio-demographic characteristic, such as gender or ethnicity.  This characteristic helps to explain differences in opinions, according to a new study on the persistence of disagreement by Isabel Melguizo, published in the April 2019 issue of The Economic Journal. 

Disagreements are part of everyday life and current research shows that are likely to persist where people relate more closely with others similar in ethnicity, age or gender.  For example, in 1987 the American public were asked whether the government should guarantee every citizen enough to eat and a place to sleep. Then 80% of black people agreed compared to 55% of white people. For more than 25 years these percentages have remained almost constant.

While disagreements regularly occur, they can have negative consequences for society by increasing the likelihood of conflict and delay agreements being reached.    

In her study, Isabel Melguizo demonstrates how group opinion is formed and evolves when individual opinions are shaped according to what they hear from others.  While not everyone’s opinion deserves the same attention, the author shows that where they share socio-demographic characteristics, such as gender or ethnicity, they communicate more intensively. 

The author concludes that it is natural to think that the issue shapes differences of opinion in society.  For example, polls since the shooting of the unarmed black teenager Michael Brown by a white police officer in 2014 in Ferguson, Missouri, demonstrates that blacks and whites see the incident very differently.  80% of black individuals thought the event raised important race issues, compared to 37% of white individuals.  This shows that the issue, whether the incident raises race issues, is related to ethnicity and therefore the polarisation is likely to be based on this. 

The researcher says that this has an important implication.  If issues make the disagreeing groups to be different, such as different ethnicity or gender, it is in the interest of politicians to raise specific issues to differentiate from their opponents and to win votes.  Therefore, the choice of the issue in a political campaign has an important strategic component. 

Homophily and the Persistence of Disagreement’ by Isabel Melguizo is published in the April issue of the The Economic Journal.

Isabel Melguizo

Assistant Professor at Centro de Investigación y Docencia Económicas (CIDE), México City