Patent protection is intended for incremental improvements but rather for unexpected, unpredictable significant advances. In exchange for making those advances public and practicable, we grant the reward of exclusive practice of the invention for a period of years. After that anyone can practice the art.
Companies are highly incented to play patent extension games.
Benjamin Franklin promoted the patent system, writing it into the US Constitution.* Yet, interestingly while he made many useful advances refused to patent them and thus gave them to the public.** That is quite a contrast to the patent games we play today.
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