The price-aggressive discount format, popularized by chains such as Aldi and Lidl, is very successful in most Western economies. Its success is a major source of concern for traditional supermarkets. Discounters not only have a direct effect on supermarkets’ market shares, they also exert...

This paper proposes a measure of dynamic comovement between (possibly many) time series and names it cohesion. The measure is defined in the frequency domain and is appropriate for processes that are costationary, possibly after suitable transformations. In the bivariate case, the measure...