Why 90% of French Jobs Become Career Traps

Over 90% of jobs in France function as career bottlenecks—positions that workers can easily enter but struggle to leave, even when better opportunities exist elsewhere—according to groundbreaking research that used statistical physics to analyze labor market dynamics.

The study reveals a hidden rigidity in modern job markets that helps explain why career transitions remain so difficult despite rapid technological change and evolving economic demands.

Researchers from École Polytechnique in Paris analyzed data from 30 million French workers over a decade, creating the most comprehensive map of occupational mobility ever attempted. Their findings challenge conventional wisdom about job flexibility and offer new insights into why labor markets respond so slowly to economic shifts.

The Physics of Career Movement

The research team applied network analysis tools typically used in statistical physics to understand how workers move between different occupations. They discovered that most jobs fall into predictable categories based on two key metrics: transferability and accessibility.

“On one hand, Transferability captures how diverse the set of occupations is that people move into from a given occupation. Accessibility, on the other hand, measures how diverse the origins are of people entering a given occupation, indicating how broadly accessible it is from across the labor market,” explained Max Knicker, lead author and PhD candidate at École Polytechnique’s EconophysiX lab.

Using these metrics, the researchers mapped all occupations onto a two-dimensional framework that revealed four distinct job categories, each with unique mobility characteristics.

Four Types of Career Paths

The analysis identified four main clusters of occupations with dramatically different mobility patterns:

• Hubs: Jobs like retail sales that are easy to enter and offer many exit opportunities
• Condensers: Roles such as caregiving that welcome diverse backgrounds but trap workers afterward
• Diffusers: Specialized positions like technical flight managers that require specific training to enter but enable transitions to many other areas
• Channels: Highly specialized roles like industrial welding operators that are both hard to access and hard to leave

The most troubling finding? The vast majority of occupations fall into the “condenser” category—jobs that many workers can enter from diverse backgrounds but which offer limited options for moving onward.

The Data Behind the Discovery

The research represents an unprecedented analysis of labor market dynamics. The team worked with comprehensive administrative data from INSEE, France’s National Institute of Statistics, tracking every worker and employer in the country over a full decade.

“We used official data provided by the National Institute of Statistics and Economic Studies through the service of Secure Data Access Center (CASD). In total, we had access to information on about 30 million workers and employers in France, whom we tracked over a 10-year period,” Knicker noted.

This massive dataset allowed the researchers to move beyond samples or projections to analyze the entire French labor market’s structure and dynamics.

Why This Matters Now

The findings come at a crucial time when technological advancement and economic shifts demand greater worker mobility. Many professions that were in high demand just a decade ago may now be obsolete, while emerging jobs struggle to find qualified workers.

Yet the research reveals that occupational transition patterns have remained surprisingly stable over the past decade, despite broader technological and economic changes. This stability suggests that structural barriers to mobility are more fundamental than previously understood.

“While the broader labor market is undoubtedly undergoing structural shifts due to technological and economic change, we found that the observed occupational transition patterns have remained relatively stable over the past decade,” the researchers found.

Breaking Down the Barriers

The study’s framework offers new insights into where policy interventions might be most effective. Rather than broad-brush approaches to workforce development, the research suggests targeting specific occupational bottlenecks could yield greater results.

“Diffuser occupations are those with high transferability but low accessibility, they’re harder to enter but offer a wide range of exit opportunities,” Knicker explained. Understanding these patterns could help identify which jobs serve as natural stepping stones to career advancement.

For example, while caregiving roles often trap workers despite being accessible, specialized technical positions may offer pathways to diverse career opportunities for those who can gain entry.

Real-World Implications

The research has immediate practical applications for policymakers, employers, and workers navigating career decisions. By identifying which occupations function as bridges versus bottlenecks, stakeholders can design more effective retraining programs and career development strategies.

“With our work, we aim to identify the occupations with the greatest potential to act as levers or bridges, facilitating people’s movement from one job to another,” Knicker explained.

The findings also help explain why traditional job placement strategies often fail. Simply matching workers to available positions ignores the underlying network structure that determines long-term career trajectories.

Looking Ahead

The researchers are making their methodology available for application to other countries and regions, potentially creating a comprehensive map of labor market dynamics across Europe. However, data standardization remains a challenge, with some countries lacking the extensive datasets available in France.

Future research plans include tracking individual career trajectories over longer periods and integrating information about specific vocational training programs. This could reveal how education and skills development interact with occupational mobility patterns.

“For now, it’s a descriptive analysis. We’re essentially looking at the past, not building predictive models yet. But even this descriptive framework helps us understand how transitions happen,” Knicker noted.

The study represents just the beginning of applying advanced analytical techniques to understand labor market dynamics. As economic transformation accelerates, such insights become increasingly valuable for creating more flexible and responsive job markets.

Perhaps most importantly, the research offers hope that seemingly intractable problems in labor market mobility can be understood and addressed through careful analysis of underlying structures. By revealing the hidden physics of career movement, it opens new possibilities for helping workers navigate an increasingly complex occupational landscape.