Heuristic biases are pervasive in inventory decision-making, yet less is known about how individual psychological characteristics shape the degree to which decision-makers rely on such heuristics. This study examines the distinct roles of mathematics self-efficacy (MSE) and cognitive reflection (CRT) in influencing behavioral deviations in the newsvendor problem. Drawing on panel data from repeated decision-making tasks, we analyze how these constructs relate to systematic biases including demand chasing, stockout aversion, waste aversion, and pull-to-center behavior. The results reveal a clear behavioral distinction between motivational and cognitive mechanisms. Higher MSE is associated with significantly lower overall deviation from the optimal order quantity, suggesting that confidence in mathematical ability stabilizes performance and promotes rule-consistent decision-making over time. In contrast, CRT robustly mitigates reactive and heuristic-driven adjustments, substantially reducing overreactions following stockouts and excess inventory, as well as sensitivity to recent demand signals. These findings indicate that analytic reasoning primarily operates through bias correction, whereas self-efficacy functions as a motivational regulator that enhances persistence and consistency. By disentangling the complementary effects of motivational beliefs and cognitive reflection, this study advances behavioral operations research and contributes to a deeper understanding of how individual differences shape bias mitigation in managerial decision-making contexts.

Keywords

Behavioral Operations Management, Newsvendor, Heuristics, Individual Differences, Experimental OM.