First, let's examine a (fallacious) argument for why copyright is always a good idea. It proceeds as follows: suppose that someone would release a work in the absence of copyright law. Then they can already release that work without copyright today; the law doesn't force them to protect it. Hence copyright can only be beneficial—it preserves the copyright-free content while incentivizing the creation of additional content.
The fallacy here, of course, is that sometimes people who would release a work even without copyright protection still prefer to use copyright when given the choice. If open source content is better for overall welfare than equivalent copyrighted content—a likely proposition—then if this group of people is big enough, copyright may be a net negative after all.
When might this happen? First we have to consider what induces people to create non-copyrighted content. The possibilities include:
- They are able to capture monetary returns from content even when it is legally unprotected. This is surely the case in the fashion industry, where a "first mover" benefits from setting a trend even if a horde of copycats swiftly follows.
- They derive non-monetary returns from content. Perhaps they just enjoy the process of creating content, or sharing it with the wider world. This blog is an example: I freely share my writing (even without ad revenue) because I enjoy swapping opinions with others and seeing my ideas discussed elsewhere.
My sense is that the abolition of copyright is only reasonable (although not necessarily optimal) when (1) predominates rather than (2). Under (1), where returns are monetary, it's likely that many content producers would still prefer to have exclusive rights to their content. Hence, with copyright, we'd see many producers switch from making copyright-free content to making similar copyrighted content—which, as I observed above, is necessary for no copyright to be socially optimal.
Under (2), however, the interest of the content producer is often already to spread content as freely and widely as possible. If I'm writing essays in a copyright-free world because I want to make my views more popular (or bolster my reputation), it doesn't make much sense for me to exercise copyright even when it's available.
It's still possible, of course, that someone with these interests would choose opt for copyright once it became possible. Maybe I'm writing a book that will be wildly popular and massively enhance my reputation regardless of whether I make it freely available. Then I would still write (for reputation purposes) in a world without copyright, but I'd choose to extract profits from my work once copyright law allowed me.
This seems much less likely, however, than the corresponding situation in (1). My tentative conclusion is that abolishing copyright only makes sense in fields where there is a large monetary incentive for copyright-free production. Am I missing anything?