Many economic models include random shocks imposed on a large number (continuum) of economic agents with individual risk. In this context, an exact law of large numbers and its converse is presented in Sun (2006) to characterize the cancelation of individual risk via aggregation. However, it is...

Purification results are important in game theory and statistical decision theory. We prove a new purification theorem that generalizes several earlier results. The key idea of our proof is to make use of the exact law of large numbers. As an application, we show that every mixed strategy in...

Purification results are important in game theory and statistical decision theory. The purpose of this paper is to prove a general purification theorem that generalizes many authors' results. The key idea of our proof is to make use of the exact law of large numbers. As an application, we show...

We study firms� incentives to acquire costly information in booms and recessions to understand the role of endogenous information in explaining business cycles. We find that when the economy has been in a recession in the previous period, and firms enter the current period with a...

The information content of stock prices is analysed without imposing strong restrictions on traders' preferences and the distribution of dividends. Noise in the information contained in equilibrium prices arises from endogenous asset supply, which offsets price movements due to informed trading....