This study addresses why professional legislative systems consistently draw candidates with higher levels of knowledge.

Introduction: The paper explores how political professionalism influences candidate quality. It challenges the notion that high entry barriers necessarily filter out less qualified contenders.

Data & Methods: Using regression discontinuity design and data from Chile's regional council elections, researchers analyze patterns across different electoral cycles (1989-2017). This method isolates the effect of legislative entry points by comparing candidates just above and below thresholds for professional status.

Key Findings: Professionalism creates an advantage not through exclusion but attraction. Councils with higher educational requirements attract more highly educated candidates, improving overall candidate quality despite stricter entry conditions.

Implications: This finding reframes political professionalism debates. Higher standards may enhance rather than merely restrict representation. It suggests professionalization can be a positive force for democratic development by elevating the caliber of elected officials.