The prime example of an industry that really does need such protection is pharmaceuticals. The reasons are threefold. First, the invention of a new drug tends to be extremely costly--in the vicinity of hundreds of millions of dollars. The reason is not so much the cost of inventing as the cost of testing the drug on animal and human subjects, which is required by law in order to determine whether the drug is safe and efficacious and therefore lawful to sell. Second, and related, the patent term begins to run when the invention is made and patented, yet the drug testing, which must be completed before the drug can be sold, often takes 10 or more years. This shortens the effective patent term, which is to say the period during which the inventor tries to recoup his investment by exploiting his patent monopoly of the sale of the drug. The delay in beginning to profit from the invention also reduces the company's recoupment in real terms, because dollars received in the future are worth less than dollars received today. And third, the cost of producing, as distinct from inventing and obtaining approval for selling, a drug tends to be very low, which means that if copying were permitted, drug companies that had not incurred the cost of invention and testing could undercut the price charged by the inventing company yet make a tidy profit, and so the inventing company would never recover its costs.

So pharmaceuticals are the poster child for the patent system. But few industries resemble pharmaceuticals in the respects that I've just described. In most, the cost of invention is low; or just being first confers a durable competitive advantage because consumers associate the inventing company's brand name with the product itself; or just being first gives the first company in the market a head start in reducing its costs as it becomes more experienced at producing and marketing the product; or the product will be superseded soon anyway, so there's no point to a patent monopoly that will last 20 years; or some or all of these factors are present. Most industries could get along fine without patent protection.

I would lay particular stress on the cost of invention. In an industry in which teams of engineers are employed on a salaried basis to conduct research on and development of product improvements, the cost of a specific improvement may be small, and when that is true it is difficult to make a case for granting a patent. The improvement will be made anyway, without patent protection, as part of the normal competitive process in markets where patents are unimportant. It is true that the easier it is to get a patent, the sooner inventions will be made. But "patent races" (races, induced by hope of obtaining a patent, to be the first with a product improvement) can result in excessive resources being devoted to inventive activity. A patent race is winner take all. The firm that makes an invention and files for a patent one day before his competitors reaps the entire profit from the invention, though the benefit to consumers of obtaining the product a day earlier may be far less than the cost of the accelerated invention process.