Imagine this scenario: Two commercial fishermen head out to sea at the break of dawn, and spend the next ten hours hauling in the day's catch. When they wearily return to dock and count their take, one has three times as many fish in his hold. How should the two fishermen be compensated for the long day's work?
Many people consider this a no-brainer. Three times the fish, three times the pay--simple. Reward is based on merit--in this case, successful fishing. In academic jargon, it's called "merit-based distributive justice."