We present a model where society is partitioned into groups, or communities, whose preferences may conflict. In particular, the actions of members of a certain group can inflict negative spillovers on members of other groups. We show that, on one hand, coordination at the group-level may be...

The presence of excess covariance in financial price returns is an accepted empirical fact: the price dynamics of financial assets tend to be more correlated than their fundamentals would justify. We advance an explanation of this fact based on an intertemporal equilibrium multi-assets model of...