The article explores how exchange rates between currencies like the Deutsche mark, U.S. dollar, and Yen are related over time. Instead of just looking at simple connections, the researchers used a method called the conditional copula to understand how these rates depend on each other. They found that the relationship between these exchange rates changes over time and is stronger when the U.S. dollar is getting stronger compared to other currencies. They also discovered a big change in how these rates are connected after the euro was introduced.