Depth or Breadth? How Skill Profiles Shape Promotion Decisions in Internal Labor Markets

Understanding how experience shapes promotion to managerial roles is of central interest to both organizations and employees. Prior research offers competing views on whether advancement favors skill specialization or broader experience, yet provides limited insight into how organizations evaluate these dimensions when making promotion decisions. Drawing on a signaling perspective, we examine how specialization relative to a promotion job and accumulated skill variety function as distinct but partially overlapping signals of promotability. Using personnel records and job descriptions from a large international pharmaceutical company, we analyze 28,699 candidate-job observations involving 1,104 employees considered for promotion to 117 managerial positions over four years. We find that both specialization and skill variety independently increase promotion chances, but in a less-than-additive manner, such that each can compensate for the other. We further show that the informational value of these signals varies with job characteristics and relational context, including social capital. These findings advance a phenomenon-based understanding of promotion decisions and inform debates on specialization, experience variety, and talent management in contemporary internal labor markets.