We propose a class of new robust GMM tests for endogenous structural breaks. The tests are based on supremum and average statistics derived from robust GMM estimators with a bounded influence function. They imply a bounded linearized asymptotic bias of size and power under local model...

In this paper we investigate portfolio coskewness using a quadratic market model as return generating process. It is shown that portfolios of small (large) firms have negative (positive) coskewness with market. An asset pricing model including coskewness is tested through the restrictions it...