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...

This chapter focuses on the geometry of how a market can solve systems of equations from market jaws to the newton method. Since market equilibrium can be interpreted as a solution to a system of equations, price discovery, as it called in the language of market makers, can be viewed as having...