<Li> Publicly shared resources <Ul> <Li> Spam email degrades the usefulness of the email system and increases the cost for all users of the Internet while providing a benefit to only a tiny number of individuals . </Li> <Li> Vandalism and littering in public spaces such as parks, recreation areas, and public restrooms . </Li> <Li> Knowledge commons encompass immaterial and collectively owned goods in the information age . <Ul> <Li> Including, for example, source code and software documentation in software projects that can get "polluted" with messy code or inaccurate information . </Li> </Ul> </Li> </Ul> </Li> <Ul> <Li> Spam email degrades the usefulness of the email system and increases the cost for all users of the Internet while providing a benefit to only a tiny number of individuals . </Li> <Li> Vandalism and littering in public spaces such as parks, recreation areas, and public restrooms . </Li> <Li> Knowledge commons encompass immaterial and collectively owned goods in the information age . <Ul> <Li> Including, for example, source code and software documentation in software projects that can get "polluted" with messy code or inaccurate information . </Li> </Ul> </Li> </Ul> <Li> Spam email degrades the usefulness of the email system and increases the cost for all users of the Internet while providing a benefit to only a tiny number of individuals . </Li> <Li> Vandalism and littering in public spaces such as parks, recreation areas, and public restrooms . </Li>

Who has proposed which solution to the tragedy of the commons