> This is a tradeoff, because it does mean that the consumer pays more for copies than the "correct" free market price
Important to keep in mind that it's not just a tradeoff because it increases marginal cost, it's a tradeoff because it outright restricts the creation of new content.
In creative industries, it means that creators are sometimes unable to build on or adapt creative work to apply to new situations or to expand on artistic ideas. Many market consequences extend from this restriction for better and for worse -- there's a reason why Nintendo games don't work on PCs or have certain accessibility features, there's a reason why backing up save data for many of their games is still a giant pain in the neck, and it's because it's illegal for other companies to create those features for Nintendo games.
IP law also has the consequence of drastically raising the barrier of entry to creating new IP, since assets and universes can't be reused or repurposed without contracts.
And of course, this also has the consequence that certain utility innovations can't happen -- E-Readers in particular have been hobbled for a long time, not just because of patent law but because existing platforms are allowed to make it illegal to transfer legally purchased books into different ecosystems. This reduces market competition in the space, artificially driving up the cost of not just the content itself, but also much of the hardware used to consume that content. There are a lot of things we could build in the E-Reader space around universal annotations, accessibility features like live-reading, etc. IP law restricts a lot of that stuff, you may not build a competing E-Reader that reads EBooks purchased on Amazon.
This obviously has consequences for the market itself; by embracing IP law, we have chosen to effectively kill off and completely eliminate competition in several areas of the free market, while making it illegal to build some meta-layers on top of platforms without enormous amounts of capital and negotiation power.
But it also obviously has cultural consequences since building on top of existing work and sharing cultural experiences (including stories) is something that is basically built into our DNA as human beings.
So we can debate whether there are advantages to IP law and whether they're wortwhile, but I do want to push back a little bit on the idea that marginal cost is the main consequence of Copyright. It's not, Copyright is a choice we've made to artificially eliminate certain parts of the market and to make certain projects and innovations practically impossible to build by anyone other than the biggest players in the market. It's not just about books getting more expensive, Copyright is a system with real tradeoffs, it increases the production of a specific kind of art at the tradeoff of drastically reducing the production of other kinds of art, and at the cost of shaping how art gets distributed and consumed and what things we can do with it, even privately.