Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We investigate the informational content of prices in financial asset markets. To do so, we use a large number of market experiments in which the amount of information held by traders is precisely observed. We derive a new method to estimate how much of this information is incorporated into market prices. We find that public information is almost completely reflected in prices but that surprisingly little private information—less than 50%—is incorporated into prices. Our estimates therefore suggest that, while semistrong informational efficiency is consistent with the data, financial market prices may be very far from strong-form efficiency.