Limited vs. Unlimited recap Just to look at the economic calculation of limited vs. unlimited once again: treating copyright as a serious of annuities let's people have a sensible discussion over how long copyright should be before it becomes, in essence, "unlimited" (and hence, unconstitutional). If people just argue over length in years, it's very difficult to agree on anything -- is 100 years more or less justified than 50? By how much?

But by recasting the question as "how close in % terms can you get to 'unlimited' and still count as 'limited'" leads to more intelligent conversations. You've got to be on someone's payroll to claim that 99% of unlimited equals limited, but people can disagree whether the level should be set at 95%, 50%, or 30%.

At 5% discount rate:
95% of unlimited is 60 yrs
50% of unlimited is 14 yrs
30% of unlimited is 7 yrs

At 7% discount rate:
95% of unlimited is 43 yrs
50% of unlimited is 10 yrs
30% of unlimited is 7 yrs