Human cooperation, occurring without reciprocation and between unrelated individuals in large populations, represents an evolutionary puzzle. One potential explanation is that cooperative behaviour may be transmitted between individuals via social learning. Using an online social dilemma...

The Government of Colombia imposes a variety of taxes that must be paid by individual wage earners, called in their entirety "social protection contributions". Since 2007 individual payments have been collected using an on-line mechanism. In order to improve compliance, the Government used a...