Catalonia is Spain's wealthiest region. Catalonia makes up 16% of Spain's population, and its €215.6bn economy creates at least 20% of the Spanish GDP. Catalonia attracts tourists and about €37bn of foreign investment. Spain's economic crisis in 2008 fueled pro-independence groups. Many Catalans felt that Madrid's taxes drain Catalonia's economy. Economics professor Elisenda Paluzie said Catalan residents contribute 20% of Spain's taxes but receive just 14% back for public expenses. At the same time, Catalonia is a wealthy region; Catalonia has lower unemployment than Spain. Compared to the rest of Spain, Catalans tend to feel more well off. 
Catalonia pays more in tax than any other region in Spain, and their contributions make up 20% of Spain’s GDP. Catalonia does not receive back its fair share from the tax money it contributes, which goes toward propping up more impoverished regions. Separatists claim they lose approximately 16 billion euros a year. Catalonia unfairly over-contributes to the rest of Spain, resulting in a fiscal deficit. Separatists argue that Catalonia would be able to keep all its tax revenues as an independent nation and would therefore be better off.  Catalonia is wealthy and could easily survive as an independent nation. It has the biggest GDP of any region in Spain, with an economy the size of Denmark. The Catalan region produces cars, food, and chemical products worth an estimated 71 billion euros in foreign exports. It also receives a large share of Spain’s tourism. So long as Catalonia remains part of the EU, its export figures would remain the same, and a break with Spain would not economically damage it. This prosperity is evident too, with Catalans more likely than other Spanish people to feel wealthy, and unemployment is lower in the region than elsewhere. Catalonia is wealthy enough to stand alone as a nation and benefit economically from no longer providing support to other regions of Spain.
The cost of independence would be massive. An independent Catalan government would have to install costly new infrastructure to implement independence. The creation of a Spanish-Catalan border could potentially be economically harmful to Catalonia, as one-third of their exports are to other regions in Spain. Catalonia would also face a large amount of debt. Their fair share of total Spanish debt once they split, is estimated to be around 72.2 billion euros. Upon independence, Catalonia would no longer be a European Union (EU) nation. It would have to renegotiate trade tariffs with all EU member countries and the prospect of rejoining the EU. Many companies will seek to move their headquarters out of Catalonia. All this may result in a drop in tax revenue and a rise in unemployment. The tax deficit is not unfair to Catalonia. Tax money is never evenly distributed, and those with the broadest backs carry the most weight. This structure is normal in most countries. Many regions of Spain have even bigger deficits. The exaggeration of the disparity between money-in/money-out of the region is often for political gain.
[P1] Catalonia gives more in taxes than it receives in benefits from Spain. [P2] Catalonia is one of the wealthiest parts of Spain and could easily survive as an independent nation. [C] Catalonia can support itself and should break from Spain.
Rejecting the premises
[P1] Tax deficits are normal and do not amount to a form of robbery. Catalonia does not have the biggest tax deficit in Spain. [P2] There are many hidden costs to independence that have not been recognized by the separatists including the negotiation of new trade tariffs and the cost of large-scale infrastructure projects.