The researchers looked at how financial and real business cycles have changed over time in OECD countries. They found that during the "great moderation" period, real business cycles became smaller, but asset price cycles became more volatile. This was partly due to the banking sector behaving in a way that made economic ups and downs more extreme. The study also showed that when economic cycles in different countries or within the same country are more in sync, it can lead to more severe crises.