The Effects of Ambiguous Information on Initial and Subsequent IPO Returns
研究了招股说明书中软信息（风险披露）的模糊性如何影响IPO的初始回报和后续回报，发现软信息与回报显著相关，支持模糊性影响投资者投资组合选择的观点。
Newly public companies must disclose significant risk factors in the offering prospectus. These disclosures are examples of “soft” or ambiguous information. Ambiguity models predict that investors will alter their portfolio weights and react to subsequent signals about such information. We test for these effects in a sample of 1,398 initial public offerings (IPOs) using word count ratios between soft and hard information as measures of ambiguity. We find a significant relationship between the soft information on risk and both initial and ex post measures of returns. These results support the view that soft information embeds ambiguity and that it influences investors’ portfolio choices.