Investor response to Morningstar's ratings, category information, and alpha in the Japanese mutual fund market

Mutual fund investors evaluate fund managers' skills before making investment decisions. Previous studies worldwide examined the rationale behind retail investors' investment decisions and found that investors reward performance by net fund flow. A Japanese study found that investors respond to alpha but do not risk factor-related returns. Surprisingly, the result would mean that Japanese investors are more sophisticated than US investors because the literature reported that US investors respond to factor-related returns without distinguishing them from alpha. We explore the background of this result in the Japanese market. This study focuses on the effects of Morningstar's fund ratings, its categories, and salient gross returns, which are readily available to investors unlike alpha. We find the following results: (1) Morningstar's rating does not substitute alpha, indicating that our result differs from the US results. (2) Investors respond only to high category excess returns, but it is a unique effect different from alpha. (3) Salient gross returns do not have a concrete relation with alpha. Moreover, we find solid convex relationships between alpha and fund flows. Investors' responses are limited to a few extreme flows; other than these, they do not respond to alpha. This extreme flow can explain the reactions to alpha on average reported in previous studies. In addition, we find that the category excess return has similar features. The solid convexity reveals that the Japanese mutual fund market is far from sophisticated, consistent with the literature. These results reveal the importance of fund distributors' behavior and information disclosure regulations.