 The paper demonstrated that in static Arrow-Debreu economies with complete markets, extrinsic uncertainty (where no fundamentals of the model are stochastic) cannot matter to equilibrium allocations.They then showed that when some agents were restricted in their trades, so that market completeness was violated, sunspots could matter, i.e.there could exist rational expectations equilibria in which equilibrium prices depended on the realization of an extrinsic stochastic process.