Carlotti’s research drew on extensive fieldwork in Senegal, interviews with consular officials and policymakers, and the analysis of 20 years’ worth of visa application data from Senegal and Nigeria. ‘Visas are often presented as neutral administrative tools,’ he says. ‘But what my research shows is that they function as powerful instruments of selection. They determine who is allowed to move and who is effectively immobilised, long before anyone reaches Europe.’

Bureaucratic, digital and financial barriers

At the centre of the research is the concept Carlotti calls “restrictive selectiveness”. EU visa systems increasingly differentiate between applicants, creating layers of bureaucratic, digital and financial barriers that disproportionately affect people from West Africa. These barriers include difficult-to-access appointment systems, high non-refundable fees, long travel distances to consulates, and opaque decision-making processes.

One of the key findings relates to the role of profiling in visa decisions, with consular authorities routinely assessing applicants based not only on their documentation, but also on assumptions about their likelihood to overstay. Carlotti analysed data on individual factors of visa applicants (such as gender, age and civil status) and found the peak of rejections was for those aged between 26 and 35 (e.g. 65.79% for Senegal, and 77.14% for Nigeria). ‘In contexts of economic inequality, characteristics such as being young, single or from a particular country can be enough to mark someone as a “risk”,’ says Carlotti.

Outsourced to private companies

The research also highlights how visa processing has increasingly been outsourced to private companies. While outsourcing is often justified as a way to improve efficiency, Carlotti shows that it frequently creates new obstacles. Applicants must navigate complex online systems, pay additional service fees, and, in some cases, rely on informal intermediaries to secure appointments. When visas are denied, applicants lose significant sums of money with no clear explanation or possibility of appeal.

‘These systems are presented as technical and neutral,’ Carlotti says, ‘but in practice they shift costs and risks onto applicants, making exclusion less visible and less accountable, and actually deterring people from applying.’

Win-win-win solutions?

Beyond tourism and short-term travel, the thesis also examines EU-backed temporary labour and circular migration programmes. While often promoted as “win-win-win” solutions for Europe, the countries of origin, and the migrants themselves, Carlotti says that these programmes often reproduce the same selective logic, with access tightly controlled and rights are limited, reinforcing unequal power relations between Europe and African partner countries.

Importantly, the research challenges the widespread perception that undocumented migration is simply the result of individual choices. ‘When legal mobility channels are systematically blocked or made inaccessible, people are left with very few options,’ Carlotti says. ‘Visa regimes play a central role in producing undocumented migration by denying legal pathways in the first place.’

Mobility is more than movement

Carlotti’s findings contribute to growing debates on global inequality, migration governance and the externalisation of European borders. Showing how exclusion happens through everyday administrative practices, Carlotti calls for greater transparency, accountability and fairness in visa decision-making.

‘Mobility is not just about movement,’ Carlotti says. ‘It is about access to opportunity, dignity and equal treatment. Understanding how visa systems work is a crucial step towards addressing the deep inequalities that shape who gets to move in today’s world.’