"In aggregate models, costs that penalise changes in investment--investment adjustment costs-- have been introduced to help account for a variety of business cycle and asset market phenomena. In this paper, we evaluate empirical evidence for these types of costs using US and UK industry data. We...

We derive asymptotic properties of estimators and test statistics to determine - in a grouped data setting - common versus group-specific factors. Despite the fact that our test statistic for the number of common factors, under the null, involves a parameter at the boundary (related to unit...