中文摘要：

本文以2006-2012年A股并购事件为样本,检验了企业出于应对风险目的所实施并购的效果及机理。研究发现：高风险企业并购后的风险持续下降,超危企业仅在中短期趋于下降。并购通过缓解信息不对称（信息效应）及获取资源（资源效应）降低风险,具体而言,信息效应仅在短期有效,资源效应在风险下降期间均有效且占主导。进一步研究发现,高风险企业短期内融资约束的缓解（融资效应）占主导,中长期内竞争优势的增强（经营效应）和融资效应均有效;超危企业短期内融资效应占主导,中期内经营效应占主导。

英文摘要：

Using the events of mergers during 2006-2012 as sample,we test the effects and mechanisms of the mergers which are used for corporate risk-resolution.We find that after implementation of mergers,the risk of high-risk companies presents declination continuously,while the risk of dangerous companies presents declination only in the short and medium term.The mergers reduce the risk of high-risk or dangerous companies by alleviation of information asymmetry（information effect）and acquisition of the targets＇ resource（resource effect）.Specifically,the validity of information effect only exists in the short term,while the validity of resource effect exists during the risk-reduction periods and always plays dominantly role.Further findings show that among high-risk companies the relief of financial constraints（finance effect）play dominantly in the short term,the strengthening of competitive advantages（operation effect）and finance effect play an important role in the medium and long term simultaneously,while among dangerous companies finance effect plays dominantly in the short term and operation effect plays dominantly in the medium term.