A new study by ETH researchers shows that the success of anti-immigration parties in Switzerland's border regions is not due to the effects of migration itself, but rather to their rhetoric.

In brief:
- A new study has investigated the success of anti-immigration parties in Switzerland's border regions following the introduction of the free movement of people in 2004.
- The authors of the study found no evidence to support the hypothesis that actual or perceived negative consequences of immigration are behind the success of anti-immigration parties.
- A series of indicators suggest that anti-immigration parties do not only respond to the real problems of the people living in border regions, but also incited or amplified their worries and concerns by adopting a new density stress narrative.
The success of right-wing, anti-immigration parties in Europe is often attributed to the fact that their policies are centred around the negative effects of immigration. According to this explanation, people mainly vote for these parties because they are worried that increasing levels of immigration will result in them losing their jobs, paying higher taxes or rents, or seeing their cultural identity threatened.
A new study by researchers from ETH Zurich and Bocconi University in Milan, which was recently published in the journal external page American Political Science Review , tested out this theory in all Swiss municipalities and cities located less than 30 minutes' drive from the national border. It concentrated on the periods before and after 2004, when Switzerland fully opened its borders to EU citizens for the very first time following the introduction of the free movement of people.
Natural experiment
What sets the study apart from similar investigations is its sophisticated and quasi-experimental design: the researchers compared the voting behaviour of people living in two regions that were affected by immigration to very different degrees: municipalities and cities close to the border (0 to 15 minutes' drive) and, as a control group, municipalities and cities located 15 to 30 minutes' drive from the border. Due in particular to the high number of cross-border commuters in the border region, the proportion of foreigners is much higher here than in the control group following the opening of the borders.

With the introduction of the free movement of people, the vote share for anti-immigration parties - such as the SVP, the Ticino League (Lega dei Ticinesi) and the Geneva Citizens' Movement (Mouvement citoyens genevois) - in National Council elections has increased by a full six percentage points in border communities compared to municipalities located 15 to 30 minutes away from the border. To explain this drastic increase, the study authors investigated the negative consequences of the free movement of people that could explain the disparity in the election results of the two regions.
"Since the border regions and communities further inland were shaped by similar political and economic conditions before the border opening in 2004, this setting provides an opportunity to disentangle the impact of increased immigration on the success of anti-immigration parties from alternative explanatory factors", explains Dominik Hangartner, ETH Professor of Public Policy and one of the study's authors.
Economic and cultural concerns play no role
To their surprise, however, the researchers found no evidence to suggest that the increase in the number of foreigners in border regions after 2004 had negative effects on the resident population - neither real nor perceived. Since the majority of EU foreigners were people from the border areas of neighbouring countries who shared a common language and culture with the native population, the researchers reasoned that the popularity of anti-immigration parties is unlikely to be attributed to cultural concerns.
Economic concerns also appear not to play a role: the study found no evidence that the influx of foreign workers has a negative impact on average wages or employment levels in communities close to the border. On the contrary: wages have even improved slightly. "Anti-immigration parties have won additional votes in border communities, despite the fact that people there are no worse off in the labour market as a result of the border opening", says Andreas Beerli, economist at the Swiss Economic Institute at ETH and one of the co-authors.
Also, with regard to traffic congestion - one of the most visible indicators of density stress - the researchers did not observe any systematic differences between border communities and municipalities and cities located 15 to 30 minutes from the border. As the traffic situation has worsened in both regions to a similar degree, this does not explain why anti-immigration parties are gaining more traction in border communities.
These findings are further supported by representative surveys measuring the population's subjective perception both before and after the border opening: "The survey data provides no indication that Swiss people living in border regions are more worried about unemployment, increasing rent costs, terror attacks or the weakening of their traditions since the introduction of the free movement of people than those living in municipalities further from the border", says Beerli.
Density stress narrative catches on
After the researchers had ruled out the most common explanations, they investigated the approach to political communication adopted by anti-immigration parties. What stood out was that, from 2004 onwards, the SVP in particular began using a new narrative around the term "density stress" in an effort to frame the negative effects of immigration.
This narrative links immigration to overcrowded public transport services, congested roads, and urban sprawl. "The density stress narrative has caught on among broader sections of the population as it expresses an uneasiness around immigration without using terms with xenophobic connotations", explains ETH professor Hangartner. The researchers suspect that this kind of political communication has contributed to the success of anti-immigration parties in border communities.
The study authors found several indications of this: first of all, they found that the density stress narrative has been particularly prominent in the media from 2004 onwards. Furthermore, using the example of Ticino, they showed that anti-immigration parties were particularly active in the border regions following the border opening - much more active than in municipalities located 15 to 30 minutes from the border. For instance, parliamentarians from the SVP and the Ticino League who represent the border regions submitted significantly more anti-immigration motions in the cantonal parliament than their party colleagues from more distant municipalities. These initiatives often make explicit reference to the density stress narrative.
Based on survey data, the authors also find that moderately politically interested citizens in the border regions were the most receptive to the arguments of anti-immigration parties. This aligns with established theories, as people with either a strong interest or no interest at all in politics are much harder to persuade.
Together, these findings suggest that anti-immigration parties focused on border communities with their density stress rhetoric and that this narrative was effective at persuading voters who are neither highly interested nor completely disinterested in politics. "In border regions, anti-immigration parties not only respond to the population's problems - they also arouse and fuel these fears through their rhetoric. They shape the public discourse and seem to benefit from the topic of immigration even when immigration has no measurable, negative effects for most people", explains Andreas Beerli.
References
Alrababah A, Beerli A, Hangartner D, Ward D, The Free Movement of People and the Success of Far-Right Parties: Evidence from Switzerland's Border Liberalization, American Political Science Review (2024) 1-20, doi: external page 10.1017/S0003055424001151