If case you hadn't noticed, I donate blood and blood products on a regular basis. They used to pay people for blood, but went to a strictly voluntary system years ago. There have been studies demonstrating that blood collection centers actually achieve a higher turnout if they don't offer compensation to donors. They probably get a higher-quality product. If I'm not getting paid, I don't have any incentive to use deceit in order to donate. Which got me thinking, are there transactions other than blood where voluntary donation yields better results than compensation?
Turns out there's a field of economics asking the same question. I read an interesting article in Ode Magazine, called "The altruism in economics". The article covers the blood donation scenario, along with something called the Ultimatum Game. In the game, two players are given a sum of money to share. Player A is to offer a portion of the sum to Player B. If B accepts, they share according to A's offer. If B rejects, both players get nothing. Traditional economics would say that A should offer B the minimum amount possible, since B should logically accept any offer. Interestingly though, the typical offer approaches a 50/50 split. It may be that humans have an inherent sense of fairness, or that Player A looks at it from B's perspective and (irrationally) decides that he should offer close to half in order to get B to accept.
In either case, it gives me hope for the future. When we finally realize that there is just one Earth, maybe we will learn to share.