Why 90% of French jobs become career traps

More than 90% of French jobs serve as a function of career bottlenecks – a groundbreaking study of labour market dynamics using statistical physics, even if better opportunities exist elsewhere.

The study reveals hidden rigidity in the modern job market, which helps explain why career shifts remain so difficult despite technological changes and evolving economic demand.

Researchers at the école Polytechnique in Paris analyzed data from 30 million French workers over a decade to create the most comprehensive occupational mobility map ever. Their findings challenge traditional ideas about job flexibility and provide new insights into how the labor market responds so slowly to economic shifts.

Physics of professional sports

Research teams apply network analysis tools often used in statistical physics to understand how workers move between occupations. They found that most of the work falls under the predictable category based on two key metrics: transferability and accessibility.

Transferability, on the one hand, captures the diversity of a group of occupations that people transfer from a given occupation. Accessibility, on the other hand, measures the diversity of the origins of people entering a given occupation, suggesting that it spans the widespread access from the labor market. ”

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

Four career paths

This analysis identified four major occupational clusters with distinct mobility patterns:

• Hub: Jobs like retail is easy to enter and offers many exit opportunities
• Condenser: Welcome roles such as nursing in various backgrounds, but then trap workers
• Diffuser: Professional positions such as technical flight managers who require specific training, but can transition to many other areas
• Channel: Highly specialized roles, such as industrial welding operators, are both difficult to access and difficult to leave

The most disturbing discovery? The vast majority of occupations fall into the “condenser” category – many workers can enter from a variety of backgrounds, but offer limited options for moving forward.

Discover the data behind it

This study represents an unprecedented analysis of labor market dynamics. The team worked with comprehensive administrative data from the French National Institute of Statistics Insee, which tracked every worker and employer in the country for a full decade.

“We used official data provided by the National Institute of Statistics and Economics through the Center for Services Security Data Access (CASD). In total, we have access to information about about 30 million workers and employers in France, which we tracked over 10 years,” Knicker noted.

This massive data set allows researchers to go beyond samples or predictions to analyze the structure and dynamics of the entire French labor market.

Why is it important now

The results are at a critical time when technological advances and economic transformations require greater worker mobility. Many occupations that were high demand a decade ago may now be outdated, while emerging jobs are difficult to find qualified workers.

However, research shows that despite wider technological and economic changes, career transition patterns have remained surprising over the past decade. This stability suggests that structural barriers to mobility are more fundamental than previously understood.

“Although there is no doubt that the broader labor market has undergone structural shifts due to technological and economic changes, we find that the observed career transition patterns remain relatively stable over the past decade,” the researchers found.

Break the barriers

The framework of the study provides new insights on the possible most effective policy interventions. The study shows that research targeting specific occupational bottlenecks shows that rather than a broad approach to workforce development, it can produce larger results.

“Diffuser careers are people with high transitiveness but low accessibility, which are difficult to access but offer a wide range of export opportunities,” Knicker explained. Understanding these patterns can help determine which jobs are natural stepping stones to achieve career development.

For example, although nursing roles are often struggling, while professional technical positions are available, dedicated technical positions may provide a variety of career opportunities for those who can enter.

The meaning of the real world

This study provides immediate practical applications for decision makers, employers and workers to navigate career decisions. By identifying which occupations are the role of bridges and bottlenecks, stakeholders can design more effective retraining programs and career development strategies.

“Through our work, we aim to identify careers with the greatest potential of leverage or bridges, thereby facilitating the movement of people from one job to another,” Nick explained.

These findings also help explain why traditional job placement strategies often fail. Matching workers only with available positions ignores the basic network structure that determines the long-term career trajectory.

Looking to the future

Researchers are making their approach available to other countries and regions and potentially creating a comprehensive labour market dynamic map in Europe. However, data standardization remains a challenge, with some countries lacking the wide range of data sets available in France.

Future research plans include tracking individual career trajectories over a longer period of time and integrating information about specific vocational training programs. This can reveal how education and skill development interact with career mobility patterns.

“Currently, this is a descriptive analysis. We are essentially studying the past and have not yet built predictive models. But even this descriptive framework helps us understand how transitions occur,” Knicker noted.

This study represents only the beginning of applying advanced analytical techniques to understand labor market dynamics. As economic transformation accelerates, these insights are becoming increasingly valuable for creating more flexible and responsive job markets.

Perhaps most importantly, the study provides hope that a careful analysis of infrastructure can allow for the understanding and addressing seemingly difficult problems in labor market liquidity. By revealing the hidden physics of career sports, it opens up new possibilities to help workers drive increasingly complex career landscapes.