We develop a new methodology to estimate herd behavior in financial markets. We build a model of informational herding that can be estimated with financial transaction data. In the model, rational herding arises because of information-event uncertainty. We estimate the model using data on a NYSE...

We study herd behavior in a laboratory financial market. Subjects receive private information on the fundamental value of an asset and trade it in sequence with a market maker. The market maker updates the asset price according to the history of trades. Theory predicts that agents should never...