Why do copyrighted works eventually enter the public domain?

Copyrighted works eventually enter the public domain because the primary purpose of intellectual property law is to encourage innovation by granting creators only a temporary monopoly over their work. By limiting the duration of these exclusive rights, the law ensures that creative material eventually becomes available for general use, which promotes further creativity, education, and the preservation of cultural heritage.1

The specific duration of this protection varies by country and the type of work, though the international standard established by the Berne Convention is generally the life of the creator plus 50 years. In the United States, this term has been extended to the life of the author plus 70 years. Once this period expires, the work is no longer protected by copyright and may be freely used, adapted, or distributed by anyone.12

It is important to note that while some works are born into the public domain—such as mathematical formulas—most creative works are intended to transition into this status after a set time to serve the greater social welfare.1