Doesn't this work against small-time inventors? Price it too high, and they can't afford to keep it (don't have time to sell it or build a business around it); price it too low, and someone can just buy it off them. Perhaps it could lapse sooner if you aren't paying the tax (to discourage people from just sitting on patents), but that doesn't solve patent trolling.

Remember, the rationale for the existence of patents is to "promote the Progress of Science and useful Arts", not to reward people with monopolies, which is the mechanism.

This is one of several related reasons why I hate the term "intellectual property". Ideas are not property, and shoving them into a property-rights framework and thinking of them as such leads to all sorts of perverse results.

It would be possible to, say, make it royalty free until either you tried to use it in litigation or, say, five years had passed.

If you can’t make the thing event slightly useful in five years, society doesn’t gain much for you having an exclusive monopoly on the thing. So long as the tax is low percentage wise, the yearly cost to keep it as your own would be well worth it.

Doesn't work very well for e.g. drugs, where you may have the first 10 years of the patent term effectively useless because of approval cycles, etc.

It seems fair that you should have to pay some kind of fee to reserve useful ideas. If you don't have the ability to turn ideas in to reality then they should be given to someone else who can pay the purchase price.

Add on a "use it or lose it" policy and I'm onboard. If the patent holder isn't building products with their IP or licensing it as the original author than they shouldn't be allowed to hold it.

It would disable "defensive" patent strategies where companies don't patent their actual technology, but the path to it, which is against the spirit of patents, and disable patent acquisition as an IP strategy.

Meanwhile companies like ARM, which live off IP licensing but wouldn't be punished because they're the original patent authors.