## Abstract

The classic Pareto criterion claims that all voluntary trades, even on the grounds of heterogeneous beliefs, should be encouraged. I argue that a trade without hope for Pareto improvement remains controversial. I introduce and characterize a notion of *belief-consistent* Pareto dominance to formalize this argument, which, in addition to unanimity of preferences, requires all rankings in a trade to be supported by some common beliefs that must coincide with the agents’ beliefs about the events on which all agents agree.

## Keywords

Heterogeneous beliefs Belief consistent Pareto condition Speculation## JEL Classification

D80## Notes

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