Many tests of asset pricing models address only the pricing predictions - but these pricing predictions rest on portfolio choice predictions which seem obviously wrong. This paper suggests a new approach to asset pricing and portfolio choices, based on unobserved heterogeneity. This approach...

Contrary to what traditional asset pricing would imply, a strategy that bets against beta, by going long in low beta stocks and short in high beta stocks, tends to outperform the market. We consider a market in which diversity is maintained, i.e. no single stock can dominate the entire market,...

We construct mean-variance portfolios using a factor model approach. We show the importance of portfolio allocation for large unbalanced equity data sets using the full CRSP database. We compare the performance of our portfolio construction methodology to the 1/N naive diversification strategy,...