I think this would mostly amount to the same thing as abolishing patents. Whenever a big company wanted to do something, it could create a new, small, special-purpose company--which just happens to have employees that used to work for the big company, who are paid exactly the same as they were before, and which shares an office with and gets funded by the big company, and so on--to develop the new product. It'd license all of its existing patents to the small company, too [actually, that'd be unnecessary, if the small company has opted out of the patent system]. And maybe the small company would refrain from applying for a patent on anything, but it'd allow the big company (exclusively) to learn what it does, and the big company would apply for (and get) the patents. Only the patents wouldn't do much good, because other companies that followed this strategy would probably be invulnerable to patent lawsuits.
Yes, but the difference is it would happen more gradually, rather than making it a law, and the next day everyone's patents are abolished. Plus, I think it would be a lot harder for politicians to abolish patents vs adding this one as an option. I figure there will be companies opposing this and lobbying the politicians to not support it, but it probably wouldn't be as bad for a law that abolishes them.
That sort of messing about isn't (in most countries) tolerated for tax evasion purposes, and tax authorities have a lot of experience dealing with it. It's solvable.
