Simplistic reply without substance. The EU economic growth is influenced by much more than just the integration. It can be stagnant not because but despite the integration. It could also be the case that EU integration was an attempt to improve economy but it didn't work out.
Do you think it would harm the US economy if every state instituted its own currency, put up border checkpoints, only allowed its own citizens to work and live in-state, and imposed tariffs on all the other states?
