PurposeThis study aims to examine the “external effect” of a migrated star player on their domestic sport industries. By exploring the new aspect of star power, this study provides important insight and critical implication to many relevant stakeholders in the professional sports league. Particularly, this is critical under the recent circumstance where the globalization of sports products becomes the central strategic issue of the world-class leagues.Design/methodology/approachIn this paper, the external effect of star players migrated from three Asian leagues (Japan, Korea and Taiwan) to Major League Baseball in the USA, the world-class baseball league, on their domestic league attendance demand was empirically investigated. For the analysis, comprehensive historical data from various reliable sources from each league were collected.FindingsThe findings of the paper strongly support the external effect of migrated stars significantly existing in all the three leagues. The effect is consistent across various measurements of migrated star players. More interestingly, the effect was found to be mixed across different leagues; for example, migrated star players increases in domestic league attendance in Japan, while it decreases in Korea and Taiwan. This indicates that the external effect of migrated star players depends on the characteristics of the domestic leagues. In addition, it was found that the external effect was substantial enough to compare to the effect of major demand drivers such as team winning, competitive balance and star power. For managerial implications, this study also provides revenue projections induced by the impact of migrated star players.Originality/valueThis study opens a new chapter related to star power topic and immediately calls for future studies regarding this external effect, particularly, theoretical and behavioral approaches.