中文摘要：

加强监管力度往往被认为是应对监管失效，促使企业提高产品质量的主要途径。然而，当监管体系作为一个系统发生失衡时，仅通过加强监管力度往往难以起到作用，需要对监管体系的结构进行调整。本研究的结论表明，在一个监管体系中，事前审批对企业的质量选择有负向影响，而事后监管则有正向影响。当监管体系发生失衡，出现”重审批，轻监管”的情形时，企业的研发成本将被提高，而违法成本则被降低，企业更愿意选择低质量的产品。此外，本文发现，最低质量标准作为常用的监管工具，能否发挥作用取决于事后监管的力度。

英文摘要：

Stricter regulation is always thought to be the main way against failure of regulation, and to promote the prod- uct quality. But when the regulation system loses balance, stricter regulation alone will not work, and an adjustment in the regulation system is necessary. This paper shows that the approval procedure has a negative effect on quality choice, whereas supervision has a positive effect. A regulatory system with strict approval and light supervision will improve the enterprises＇ R＆D costs, reduce the illegal costs, and make enterprises more apt to choose the low-quality products. The paper also finds that whether the MQS works or not depends on the strength of supervision.