We consider the issue of cross sectional aggregation in nonstationary, heterogeneous panels where each unit cointegrates. We first derive the asymptotic properties of the aggregate estimate, and a necessary and sufficient condition for cointegration to hold in the aggregate relationship. We also...

In this paper, we propose the use of bootstrapping methods to obtain correct critical values for dating breaks. Following the procedure proposed in Banerjee, Lazarova and Urga (1998), we consider the case of estimating a system with two or more marginal processes and a conditional process....

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...