What little experience I have with patents tends to push me to agree. It's a net negative for society.

- I got a software patent once, on a blockchain related idea. Why did I patent it? Because my partners thought that if we didn't, we'd be in a bad position if things took off. So then we had to spend time and money researching what lawyer to get, explaining to them what the invention was, and so on. Time that could be better spent building a product. And to be honest, the idea was trivial to anyone who knows how to code. But that leads me to another point...

- The fact that things can be patented leads to a culture of ideas being some sort of resource, like gold or oil. They're not. And we shouldn't deify people who have good ideas. Ideas are simply a natural consequence of exposure to an environment. Literally every idea ever has been "let's take X and Y, and use it for Z". Stick someone in the world, and they will have ideas. Sometimes two people will have very similar ideas.

- A friend of mine is an inventor. Of the old school, the kind of guy who has a 3D printer because his inventions are objects rather than software. Like any tech guy, he gets ideas. Every time he gets one, he has to spend time looking for an existing patent. He's canned several projects because something turned up. For instance my wife started doing some research in the medical field because he'd come up with some device, and it basically ended up getting canned because someone in China had done something similar. He's spent significant time training himself in how to do a patent search, which is not a trivial thing to do.

The market should just be free. You invent a better mousetrap? Why shouldn't I make it and sell it? Maybe I can sell it more cheaply. Or I can make one that fits the needs of the consumer of some segment better. Why should I be stopped?

And what about the argument that it incentivises research? I don't know what the state of the evidence for this claim is, but I would think that just about any interesting line of research will be known to more than one group of researchers.

For instance, DNA was being looked at by several groups before Watson and Crick published. In science space, it's somewhat ok, maybe it's bad that one group gets a lot more credit than those who went down a different line, but those other guys can still publish papers with valuable information.

But if you're researching a cure for cancer (imagine it's just a certain unobtainium complex), and someone else finds it first, you are screwed. In fact, if you know that many people are making progress on a problem, you have a powerful disincentive to work on it. In fact, you could even have an equilibrium where a line of research is not pursued because someone else might get ahead.

The econ 101 idea that people will invent stuff on the basis that their investment will be protected is naive. They may never get to the point where they're protected.

Aside from that, look at fields where intellectual property is not protected from copycats. Imagine if you could only buy suits from one brand. Or if baseball caps only had one logo. And so on. There's plenty of fields where me-too marketing is beneficial to society.