ABSTRACT Online labor markets have gained significant importance in recent years, drawing considerable attention in academia and practice. These platforms enable workers worldwide to sell their labor services to a global pool of clients. However, the challenge lies in motivating workers effectively to enhance their productivity. To address this issue, we employ the self—determination theory and present a model that elucidates motivation's impact on productivity across various payment schemes. Additionally, we leverage the psychological trait theory and its suggested taxonomy to explore how compensation policies in online labor markets affect incentives differently based on individual differences. Our experiment tests predictions from a formal labor supply and productivity model for workers with varying compensation levels. The results indicate that intrinsic workers exhibit higher productivity when bonus rewards are introduced. Furthermore, our study confirms the presence of heterogeneous personality effects, emphasizing that increased worker productivity is primarily associated with conscientiousness and agreeableness traits. These findings illuminate the intricate mechanisms governing worker motivation and engagement in paid crowdsourcing environments. They provide valuable theoretical and managerial insights for researchers and crowdsourcing practitioners aiming to enhance worker productivity in online tasks.