The study looked at Portugal's finances from 1999 to 2016 to see if there is a connection between the government's budget deficit and the country's external deficit. They used two methods to analyze the data and found that there is a link between the budget deficit and the external deficit. This supports the idea that when the government spends more than it earns, it can lead to a higher external deficit. The study also suggests that the relationship between the two deficits could go both ways, meaning they can influence each other.