We build a model of tacit collusion between firms that operate in multiple markets to study the effects of trade costs. A key feature of the model is that cartel discipline is endogenous. Thus, markets that appear segmented are strategically linked via the incentive compatibility constraint....

We empirically evaluate a behavioural model with boundedly rational traders who disagree about the persistence of deviations from the fundamental stock price. Fundamentalist traders believe in mean-reversion, while chartists extrapolate trends. Agents gradually switch between the two rules,...