Abstract: This document shows a comparison of bartering, alternative (free) money, official money (based on credit), and natural economies (give and take). The comparison is based on a workshop where the different kinds of exchange are simulated by means of playing cards. This paper describes the simulation game, and some reflections by the authors from previous editions of the workshop. This workshop is also offered in this conference as a special session.
Objectives: The purpose of the workshop is to claim that, rather than profit maximization, the natural objective of economic activity is to find resources to realize true necessities. Results of the simulation game show that natural economies (asking and giving without offering or expecting anything in exchange) are the most effective way to reach this end.