it is quite funny and sad how many comments focus on how this system can be abused (and implicitly why it is inefficient). I think this is a bias from our programming/hacker culture where things (aka programs) tend to work with absolute. My experience in economic policy has more to do with relatives ( a trend vs another one, the percentage of free rider vs the gain for the whole population ) and tuning ( adding counter-balance and conditions as we get feedback from the terrain ).