中文摘要：

通过对2008~2013年证券交易所债券发行的研究,本文发现发行人的违约风险越高,为债券提供信用担保和物权担保的可能性越高,道德风险理论更符合我国债券市场。研究还发现,信用担保降低了债券的发行利差,提高了债券评级;而物权担保增加了债券的发行利差,对债券评级的影响不显著。结果表明,当高违约风险的发行人提供担保后,信用担保能够降低发行利差和发行评级,而物权担保不能。因为信用担保有效缓解了信息不对称,而物权担保只是改变了发行人利用信息优势的方式。本文的启示在于：在投资者保护制度弱的环境中,信用担保比物权担保更有利于债券发行。

英文摘要：

Based on the investigation about listed bond issue during 2008-2013, we find that probability of providing assurance for bond is higher when bond issuers are more risky. Also we find that, credit assurance decreases bond issue spread and improves bond issue rating; property assurance increases bond issue spread but has no impact on bond issue rating. This suggests that credit assurance is much better than property assurance when risky bond issuers have provided assurance. Because credit assurance relieve information asymmetry efficiently, but property assurance just changes way of making use of information advantage for bond issuers. Our results tell us that credit assurance is more beneficial to bond issue than property assurance, especially in weak situation.