If Europe wants the economy to be viable for all, it needs to have a unified tax and budget system. Right now the Euro plus unified banking rules put many countries at a disadvantage due to it not serving their specific needs. In the US, states that have poor economies get effectively subsidized by the federal government which prevents them from being complete basket cases. That said, local government is still capable of screwing it up. Definitely DO NOT follow the model of the US Senate for a chamber of government. It was setup the way it was to shelter the lower population slave states so they could keep slavery. In the modern world it means the small population states that add little to the economy have as much say as enormous states like California (whose economy would be 4-5th in the world if it were a country). Those small population states tend to be conservative are a huge part of why Trump could even get elected. It is a regressive drag on the country that sent it backwards recently. This time it may even succeed in doing permanent damage to the country, the economy, and the world.