The article looks at European business cycles by breaking them down into different frequency components. They used a method called multiresolution decomposition with wavelet transforms to analyze real GDP data. The study found that euro area countries can be grouped into three categories based on their level of correlation with each other at different cycle frequencies. Some countries like France, Belgium, and Germany have high and dynamic correlations, while others like Greece show low correlations with little convergence. Finland and Ireland have low static correlation but convergent dynamic correlations.