Studies on Limitations of Copyright

本文从“市场失灵论”的角度分析了美国著作权法中关于“合理使用原则”的讨论，并对日本著作权法提出了以下三点建议：（1）使用受版权保护的作品进行批评和滑稽模仿等，应比现行判例法更宽松地处理，因为用户很难从版权所有者那里获得许可;（2）考虑到无法将使用受版权保护的作品所产生的外部利益内部化，为研究和教育目的进行复制的合法性，特别是在图书馆进行的复制，（3）在对表达自由产生寒蝉效应的情况下，或者在可能形成共同体的情况下，由于存在无法完全转化为效率的问题，因此必须更严格地保护自由领域。

Based upon the analyzes of discussions on the "fair use doctrine" in the U.S. copyright law from the perspective of "market failure approach, the following three proposals have been made with regard to the Japanese copyright law : (1) the use of copyrighted works for criticism and parody and the like should be treated more leniently than the current case law does, because it is difficult for users to get permissions from the copyright holders ; (2) considering the inability to internalize the external benefits accrued from the use of copyrighted works, legality of reproductions for the purpose of research and education, especially those made in the libraries, should be permitted within a broader range than the current Japanese Copyright Act allows ; (3) in cases which have chilling effects on freedom of expression or where the formation of community can be engendered, the realm of freedom has to be secured more tightly, since there are problems which cannot be fully translated into efficiency terms.