But not only that, the centralisation of government powers and agencies have created a problem where many big companies have to be in Madrid even if most their operations are in other parts of the country. That makes their taxes to be paid in Madrid instead of e.g. Valencia, Bilbao or Barcelona. The amount of taxes lost because of this is HUGE and much worse than the 16 billion per year above.
An independence would bring back 100% of the former and a good chunk of the latter. Hopefully that would help Catalonia grow at the pace its economy can and then it should be able to contribute back to Europe much more than now. Contributions have to be sustainable.
Edit: This comment is now at -1. Please argue instead of downvoting. You're acting against HN's rules.