  As we show using the notion of equilibrium in the theory of infinite
sequential games, bubbles and escalations are rational for economic and
environmental agents, who believe in an infinite world. This goes against a
vision of a self regulating, wise and pacific economy in equilibrium. In other
words, in this context, equilibrium is not a synonymous of stability. We
attempt to draw from this statement methodological consequences and a new
approach to economics. To the mindware of economic agents (a concept due to
cognitive psychology) we propose to add coinduction to properly reason on
infinite games. This way we refine the notion of rationality.
