This paper considers how optimal copyright enforcement is affected by the development of those media industries promoting musicians. Accounting for situations in both developing and developed countries, we point out two cases, a strictly convex and a strictly concave profit function with respect...

This paper considers privacy invasion resulting from map services, such as Street View, on the Internet. Reciprocal privacy invasion can develop into a Prisoners' Dilemma. A portal site remedies such a dilemma by supplying personal information. However, under excessive supply, it worsens agents'...

This paper considers the behaviors of homepage creators who supply as well as demand content on the Internet while facing content competition. The Internet makes possible an aspect we have not experienced with communication tools as telephone, radio, and TV. We present three propositions. The...