The Breadth Premium: Measuring the Firm-level Impact of CEO Career Breadth

Prevailing career and education systems continue to reward early specialization and deep expertise within narrow domains. While such depth promotes efficiency, it may also limit adaptability in complex and rapidly changing environments. Building on research showing that variability in training inputs enhances learning outcomes across cognitive and behavioral domains, this study explores whether the same principle applies to executive performance. Using an original dataset of 650 CEOs leading firms that together represent roughly 85% of US market capitalization, we construct a composite Breadth Index capturing cross-domain educational and professional breadth. Preliminary analyses reveal that firms led by higher-breadth CEOs outperform their industry peers by an average of 9.8 percentage points over a three-year window. Regression results indicate that each one-point increase on the five-point Range Index corresponds to a 1.8-point gain in abnormal returns (p < 0.03), with effects remaining robust across industries, firm sizes, and CEO age groups. These early findings suggest that leadership breadth, defined as experience spanning multiple functions, disciplines, and sectors, is positively associated with firm-level performance. While the dataset remains under validation, the pattern observed supports the emerging view that as specialization deepens, the marginal value of lateral insight rises. Breadth, in this light, functions as a form of adaptive capital; it enhances leaders' capacity for integrative reasoning, organizational translation, and strategic flexibility in uncertain environments.