We analyze how financial experts influence asset prices in a sequential trading model. In the model, an expert of unknown ability sends a report about asset values to traders, who then observe a signal about the expert's type. All information about the expert's ability is private to traders and...

By choosing whether or not to follow a financial expert's advice, a privately informed trader implicitly screens the ability of this expert. We explore the performance of the resulting feedback mechanism. In the medium run, feedback may altogether break down, enabling experts of low ability to...