How Brazil's Lawmakers Vote: A Tale of Two Houses

The Brazilian Congress is made up of two parts: the Senate and the Chamber of Deputies. Both are crucial for making laws in Brazil. Researchers have been using complex networks to study how these groups work. Most studies have focused on the Chamber of Deputies, leaving the Senate largely unexplored. This is a missed opportunity, as both houses have unique dynamics. Previous studies have highlighted the need for a clear method to identify the key structures within these networks. However, they often rely on guesswork or personal judgment. This can lead to inconsistent results. A new approach aims to change this by creating a systematic way to automatically identify these key structures. This new approach looks at both the Senate and the Chamber of Deputies. By comparing them, researchers can spot differences and similarities. This comparison is important because it shows how each house reacts to big events. For example, during major events in Brazil over the past decade, the Senate and the Chamber of Deputies have shown different behaviors. The study also looks at how votes are split between the government and the opposition. This adds another layer to the analysis, helping to understand the political landscape better. The findings suggest that the dynamics in both houses are not the same. Moreover, the best method to identify key structures can change over time and differs between the two houses. This research is a step forward in understanding how Brazilian lawmakers vote. It shows that a one-size-fits-all approach does not work. Instead, each house needs to be studied individually, considering the context and the times. This can help in making more accurate predictions about political behavior. It also highlights the importance of using data-driven methods in political analysis.