The public cost of a patent is the monopoly it provides. The public benefit is that the invention is eventually released into the public domain. Take the phar

The public cost of a patent is the monopoly it provides. The public benefit is that the invention is eventually released into the public domain. Take the pharmaceutical companies as an example of where patents are perhaps worthwhile: - It costs a lot of money to produce a new drug; high cost == high risk == unattractive field for investment. Patents lower the risk because the pharmaceutical companies know that they will be able to recoup their investment if they actually produce something useful. - Likewise, it costs a lot of time to do the research and produce something that works. The 20-year timescale (http://law.jrank.org/pages/9086/Patents-Patent-Duration.html http://law.jrank.org/pages/9086/Patents-Patent-Duration.html) of the patent is approximately in line with the effort expended. - It is comparatively easy to tell if a drug works. - After the patent expires, the drug is probably still useful...e.g. aspirin hasn't stopped being a good painkiller just because it's a commodity. Compare this to software patents. None of the points match up: - Production costs are zero == low risk == attractive field for investment. - Production time is almost zero. You can submit software patents literally as fast as you can write them up. - Most software patents are completely intangible and have very fuzzy edges. If you're a patent examiner in 1980, how do you verify that this "web browser" idea will in fact work? - After 20 years, the patent is likely to be worthless. As a trivial example: yes, people still use GIF but JPEG and PNG are far more common. All of these things encourage the system we have now--"throw it against the wall", patent trolling, etc--instead of what patents were Constitutionally intended to be: an incentive to grow the arts, sciences, and economy.