Information Diversity and Market Efficiency Spirals

We analyze a model where the value of a traded security is affected by two different fundamentals, e.g., the quality of the firm's technology and the demand for its products, and where there are two groups of informed traders, each one informed about a different fundamental. We analyze the interaction between the informativeness of the price about the two fundamentals and characterize when it leads to attenuation and when it leads to amplification of shocks to market efficiency. Amplification occurs because the informativeness about one fundamental reduces the uncertainty in trading on information about the other fundamental and encourages traders to trade more aggressively on such information. This effect is dominant when the informativeness of the price is relatively balanced between the two fundamentals, which implies that economies with more diverse information -- i.e., where the information is more evenly distributed between the two groups -- will exhibit positive externalities and have higher levels of overall market efficiency. Finally, we endogenize the incentives for information production and show that the above effect leads to strategic complementarities in information production.