> People invent and invest in the absence of patents
I don't think that this is established. Patents have existed since the 1400's and areas that have patent systems have general out-innovated areas without them. This could be the result of many other factors, but patents do clearly provide an incentive to innovate. I think a better argument is that the added costs of dealing with patent trolls outweighs the incentive of a temporary monopoly.
Logically, it can also have the opposite effect. If you have all the rights for a product, you have no incentive to improve it, until the patents are about to expire.
My favorite example is the Roomba. Cool new vacuum cleaner invented, ridiculously broad/abstract patents filed... result, near zero progress for 20 years.
I was thinking more along the lines of competitors who are in the same space as you (let's say, light bulb manufactures) -- you patent a new type of bulb, your competitors could patent a bunch of improvements on it to deny you future market on improved versions.
Patents have existed since the 1400's and areas that have patent systems have general out-innovated areas without them.
Has the direction of causality been established here? Maybe areas with more innovation sprout wannabe monopolists who manage to lobby their governments to create patent protections.
