Yes, on paper. The problem is in current practice. In most fields, patent system extends too much protection for the patent owners, allowing them to block an idea from being used by others for far longer than it's needed to recoup development costs and earn a solid profit on top of it.
Also, you forgot about the other part of the purpose of patents - to allow the public to benefit from the innovation, by making it public domain after patent protection expires. Increasingly, patents don't hold that end of the bargain, by being deliberately written in such a vague form as to be useless as a blueprint.
Back to the topic of pharma - this is the only case I know where I feel that cost/benefit of patents favors keeping them. Everywhere else, I feel things would be better if we abolished them, or at least severely reduced their duration.
Also, you forgot about the other part of the purpose of patents - to allow the public to benefit from the innovation, by making it public domain after patent protection expires. Increasingly, patents don't hold that end of the bargain, by being deliberately written in such a vague form as to be useless as a blueprint.
Back to the topic of pharma - this is the only case I know where I feel that cost/benefit of patents favors keeping them. Everywhere else, I feel things would be better if we abolished them, or at least severely reduced their duration.