The authors study the performance of the rational expectations hypothesis in multiperiod experimental markets with multiple assets. They find that the markets are generally inefficient from the point of view of full information aggregation. However, arbitrage relationships hold and it is not possible to detect the informational inefficiency by using some standard tests of market efficiency. These findings suggest that the lack of arbitrage opportunities and the failure of common tests to reject inefficiency are not sufficient to conclude that a market is informationally efficient.

We study the performance of the rational expectations hypothesis in multiperiod experimental markets with multiple assets. We find that the markets are generally inefficient from the point of view of full information aggregation. However, arbitrage relationships hold, and it is not possible to detect the informational inefficiency by using some standard tests of market efficiency. These findings suggest that the lack of arbitrage opportunities and the failure of common tests to reject inefficiency are not sufficient to conclude that a market is informationally efficient.