This paper proposes a two factor model for asset pricing. We formulate a model of asset returns that in addition to the traditional market return term includes also the square of the market return to account for risk originating from coskewness with the market portofolio. The quadratic term is...

We propose a class of new robust GMM tests for endogenous structural breaks. The tests are based on supremum, average and exponential functionals derived from robust GMM estimators with bounded influence function. We study the theoretical local robustness properties of the new tests and show...