The Copyright Tax

As Lawrence Lessig argues his case before the Supreme Court to try to declare the latest copyright extension unconstitutional, he might want to take this quote from Thomas Macauley.

The principle of copyright is this. It is a tax on readers for the purpose of giving a bounty to writers. The tax is an exceedingly bad one; it is a tax on one of the most innocent and most salutary of human pleasures; and never let us forget, that a tax on innocent pleasures is a premium on vicious pleasures. I admit, however, the necessity of giving a bounty to genius and learning. In order to give such a bounty, I willingly submit even to this severe and burdensome tax. Nay, I am ready to increase the tax, if it can be shown that by so doing I should proportionally increase the bounty. My complaint is, that my honourable and learned friend doubles, triples, quadruples, the tax, and makes scarcely any perceptible addition to the bounty.

Discussion Question. How does the discount rate affect the ability of copyright extension (lengthening the amount of time before a copyright expires) to provide incentives for creative work?