Halos, Performance Matching, and PSM: Experimental Evidence of Performance Appraisal Bias Among Korean Government Workers

Performance appraisal is a central human resource management tool in government, and high-quality, fair, and objective appraisals contribute to organizational performance. By contrast, biased performance appraisal undermines employee morale and, ultimately, the merit system. This study examines three sources of bias in performance evaluations: the halo effect, similarity-attraction factors between rater and rate, and public service motivation (PSM). Using a two-by-two vignette-based survey experiment and a large sample of Korean government workers, we confirm earlier findings on the biasing influence of unrelated information on performance ratings. Second, while we find no effect of gender matching, we show that raters who self-identify as high-performance employees give lower than average ratings to low-performance workers, thereby amplifying the halo effect. Finally, we find that PSM is associated with inflated performance ratings across genders and performance categories. We discuss how our results can inform efforts to improve the fairness and accuracy of employee performance appraisals.