An intellectually curious and evidently enterprising tenth-grader in California emailed me with some questions about copyright, so instead of emailing him back I figured I'd post the answers here. The questions are numbered and my answers are in blockquotes.
Here goes...
1. Besides the obvious public benefit, are there other incentives for creative individuals to place their works in the public domain instead of commercially exploiting their works through strict copyright?
1a. It's the right thing to do. Doing the right thing feels good.
1b. Until everyone puts makes their works open by placing them into the public domain or licensing them under an open license such as Creative Commons or the Open Publication License, there may be publicity value in doing so.
1c. There is no necessary conflict between making your works open and commercially exploiting them. See below.
2. How have copyright and intellectual property affected your work with open source?
2a. When I started working with open source code and open standards, I had the traditional view that creative works must be considered as intellectual property in order for society and the economy to function effectively. Now I have come to see that the metaphor of property is problematic and cannot be directly applied to creative works.
2b. The open-source community has shown that it is possible (not necessarily easy) to give away the content (e.g., software code) yet make money in subsidiary ways (e.g., consulting services or the selling of add-ons). This has opened my eyes to similar models in more traditionally creative domains. For example, even though I make my essays available for free on the Internet, I could still sell books containing the essays (because many people prefer reading books to reading web pages). Visual artists could sell posters. Musicians could sell concert tickets (fans will pay for the live experience) or merchandise such as T-shirts (fans want to show that they are fans). Poets could give in-person lectures and workshops. And so on. Creative people will find creative ways to make money even if it becomes trivially easy for others to copy their creative works. We need to start exploring these models rather than trying to hold back the tide of technological innovation.
3. In general, what problems plague the current copyright system and what sort of changes are necessary for reform?
3a. The copyright system is slowly but inexorably moving to a regime of perpetual copyright, which is not what the Founders intended. The implications of perpetual copyright are significant, such as search costs to determine who the owner is and the inability to know if one's work impinges on existing copyrights.
3b. Copyright emerged when it was relatively difficult to generate physical works such as books or maps. Therefore the costs imposed by copyright restrictions could be borne by relatively few actors, such as publishers and printers (in fact these actors pushed for copyright as a quid-pro-quo by which they would impose government censorship). As it becomes easier and easier to generate or copy digital works, the costs will be borne by everyone; for instance, it will become necessary for governments to inspect your computer and any other device that might hold digital works, monitor all your Internet traffic (which must be unencrypted in order to be monitored), etc. These measures will invade the privacy of everyone so that a few producers of "content" (mostly large corporations) will be able to enforce their monopoly over copying of digital works.
3c. We are facing a historical and technological sea change regarding the status of creative works. Given the significance of the changes underway, it is incumbent on thinking people everywhere to reflect on the meaning and status of creative works. Among other things that means moving beyond the simple but misleading metaphor of intellectual "property", because the familiar system of copyright based on the concept of intellectual property becomes very problematic when it is easy to make or copy works. I am confident that once creative people begin to see those implications, they will move to make their works more open (especially if they don't have the legal and financial resources of the large conglomerates in publishing, music, gaming, and film).
3d. I don't pretend to have all the answers. These issues are difficult to understand and, to many creative individuals, personally threatening. We need to tolerate differing viewpoints while we sort out the future of creative works in a free society. It won't be easy, but then many good things are difficult to achieve.