An anonymous reader writes "So how long should a copyright be valid for? A Cambridge student has stepped into the discussion with a dispassionately calculated estimate of the optimal period a copyright should be granted. Ars' point of view: 'Neither the US nor the UK are in any danger of rethinking copyright law from scratch, but if they were looking for guidance in how to set up their systems, Pollock has it. He develops a set of equations focused specifically on the length of copyright and uses as much empirical data as possible to crunch the numbers. The result? An optimal copyright term of 14 years, which is designed to encourage the best balance of incentive to create new work and social welfare that comes from having work enter the public domain (where it often inspires new creative acts).' The original paper is available (pdf) online."