Economist calculates optimum term of copyright: 14 years!

Rufus Pollock, a PhD candidate in economics at Cambridge University, has just released "Forever Minus a Day? Some Theory and Empirics of Optimal Copyright," a brilliant new paper on the economically optimal term of copyright. He's presenting it in Berlin this week, but it's already online. Here's the abstract:
The optimal level for copyright has been a matter for extensive debate over the last decade. This paper contributes several new results on this issue divided into two parts. In the first, a parsimonious theoretical model is used to prove several novel propositions about the optimal level of protection. Specifically, we demonstrate that (a) optimal copyright falls as the costs of production go down (for example as a result of digitization) and that (b) the optimal level of copyright will, in general, fall over time. The second part of the paper focuses on the specific case of copyright term. Using a simple model we characterise optimal term as a function of a few key parameters. We estimate this function using a combination of new and existing data on recordings and books and find an optimal term of around fourteen years. This is substantially shorter than any current copyright term and implies that existing copyright terms are too long.
Link (Thanks, Rufus!)