It has already started. Over 1000 major companies (and counting) have moved their headquarters from Catalonia to other Spanish cities in the last couple of weeks. Obviously the Catalan separatists never learned from the 'Montreal Effect' that took place in Quebec in the late 70s.

https://www.ft.com/content/e91df296-b00d-11e7-beba-5521c713abf4
.
https://www.thedrinksbusiness.com/2017/10/breaking-codorniu-to-move-hq-to-rioja/