How does government microblog affect tourism market value? The perspective of signaling theory

•Based on large-scale text analysis technology, this study analyzes the post emotion of government microblog and reveals the influence of government microblog information on tourism market value.•The signal theory is adopted as the foundation of hypotheses. Mediating effect, moderating effect, and crowding-out effect are investigated.•It is demonstrated that the post emotion of government microblog significantly affects the market value via a partially mediating role of comment emotion.•It is found that tourism attention has a crowding-out effect on comment emotion, and people's impression of scenic spots will enable them to selectively look for information and comment.