Press release -
Social Media: How Algorithms Influence Election Campaigns
Milano, 18 luglio 2024 – A new study published in the journal PNAS Nexus reveals how social media algorithms favor politically sponsored content from certain parties given the same investment budget.
The research, a collaboration between the Politecnico di Milano, LMU – Ludwig Maximilians Universität of Munich, and the CENTAI institute of Turin, analyzed over 80,000 political ads on Facebook and Instagram before the 2021 German federal elections. These ads were placed by parties across the political spectrum and generated over 1.1 billion impressions during an election with more than 60 million eligible voters.
Investigating online campaign inequalities, significant discrepancies emerged in the advertising's effectiveness and the intensity with which ads reached their targets, favoring more extremist groups.
Using the collected data, it was found that over 70% of parties used user profiling in their ads. Additionally, calculating variations in advertising costs (impressions per euro spent) showed that not all parties achieved equal results with the same budget. The far-right AfD proved to be the most effective, with ads almost six times more efficient than competitors who had invested the same budget. The Greens were the least cost-effective party.
“The greater success of their advertising could be explained by the fact that the incendiary political issues promoted by populist parties tend to attract a lot of attention on social media. Consequently, algorithms would favor campaign ads with such content,” explains Francesco Pierri, a researcher from the Data Science research group of the Department of Electronics, Information, and Bioengineering at the Politecnico di Milano, who co-led the study.
Another finding of the study was the discrepancies for all parties between the targeted audience and the actual audience reached. While most parties tended to reach a younger audience than expected, the opposite occurred for the far-right. Pierri and his colleagues hypothesize that the algorithmic bias in ad distribution is based on known voter behavior.
“We see a systematic bias in how the political ads of different parties are distributed. If they aim at a specific audience or send contradictory messages on political issues to different groups, this can limit the political participation of disadvantaged groups,” Pierri continues. “Even worse, the algorithms used by the platforms do not allow verification if they involve biases in ad distribution. If, for example, some parties systematically pay higher prices than others for similar ads, this damages political competition. We need greater transparency from the platforms regarding political advertising to ensure fair and uncompromised elections.”
It is no surprise, then, that targeted political advertising on social media has raised serious concerns among political actors, researchers, and society in general. The calls to improve the monitoring of this form of electoral advertising to safeguard democratic integrity are growing stronger. Public pressure and regulatory efforts (e.g., the Digital Services Act in the EU) have pushed social media platforms to provide public access to political and social ads, allowing researchers to study them on a large scale.
Topics
Politecnico di Milano is a scientific-technological university which trains engineers, architects and industrial designers.
The University has always focused on the quality and innovation of its teaching and research, developing a fruitful relationship with business and productive world by means of experimental research and technological transfer.
Research has always been linked to didactics and it is a priority commitment which has allowed Politecnico Milano to achieve high quality results at an international level as to join the university to the business world. Research constitutes a parallel path to that formed by cooperation and alliances with the industrial system.
Knowing the world in which you are going to work is a vital requirement for training students. By referring back to the needs of the industrial world and public administration, research is facilitated in following new paths and dealing with the need for constant and rapid innovation. The alliance with the industrial world, in many cases favored by Fondazione Politecnico and by consortiums to which Politecnico belong, allows the university to follow the vocation of the territories in which it operates and to be a stimulus for their development.
The challenge which is being met today projects this tradition which is strongly rooted in the territory beyond the borders of the country, in a relationship which is developing first of all at the European level with the objective of contributing to the creation of a single professional training market. Politecnico takes part in several research, sites and training projects collaborating with the most qualified European universities. Politecnico's contribution is increasingly being extended to other countries: from North America to Southeast Asia to Eastern Europe. Today the drive to internationalization sees Politecnico Milano taking part into the European and world network of leading technical universities and it offers several courses beside many which are entirely taught in English.
