The stance of the economists making these arguments was that grievances are ubiquitous but that financing varies. Since rebellions are not so frequent, maybe it has more to do with funding and not so much with grievances. The problem is that funding requires not the existence of resources but just enterpreneurs. How so? Lootable resources requires little imagination, but rebels often have much at stake, and can imagine all kinds of ways to finance their efforts. Such as?
- Smuggling. Even if you don't have stuff to smuggle, you may have location, location, location. So, smuggling of drugs, girls and women, cigarettes, etc were a key source of income for various groups in the Balkans. Proximity to Europe was sufficient.
- Diasporas, ethnic kin, and the like minded. Lots of money flows from people who left the homeland. Similarly, those who share identity but are not from the homeland--those who speak the same language, share the same religion, are of the same/similar race--may contribute money, equipment and personnel to the cause. During the cold war, one sure way to get funding was to put a red star on your helmet if you were fighting an American ally or call the US if your adversaries could be called Communists.
- Kidnapping. This can be a big $ kind of business. One of the frustrations the US has with its allies is a willingness to pay big bucks. All the US does is trade prisoners... ooops.
- Protection. Organized criminals are not the only ones who run protection rackets--insurgencies engage in the same kind of enterprise: donate and you will not be harmed. Tilly made this clear a while back. The Viet Cong taxed the people in the areas they controlled with their punishment for tax evasion being just a bit more "kinetic" than the penalties the IRS imposes.
Given that the Rebels required a constant supply of non-Imperial ships (they could not just steal from the Empire as the Empire did not use X-wings, Y-wings, A-wings and the like), they had to have money from somewhere. Sure, they allied with smugglers (Han, Chewie and their pals), but did they rely on smuggling glitterstim and other forms of drugs to fund the alliance? Not so clear. They may have tried to work with the Hutts, but that was very tricky business.
It is clear that ethnic ties mattered. That the Empire, always human-centric and xenophobic, abused certain species. The Wookies, who had been enslaved, were most willing to lend their resources to the cause. The big ships were mostly made by the Mon Calamari, who had joined the alliance at the beckoning of their kin, Admiral Ackbar. They were conducive to such appeals because they too had been abused by the Empire.
The history of the Alliance contains no stories of kidnapping for profit (for romance? That is something else), but it is pretty clear they relied on protection rackets--taxing the systems that they freed from the Empire. That might look like state-building to some, but it looks like organized crime-style protection rackets to those who are fighting the rebels.
Clearly, there is a need for more fieldwork to examine the archives of the Rebel Alliance to assess how they funded themselves. Not every major figure in the alliance had the wealth of a planet and the property that comes with royalty to help finance the effort (and unless one counts mining concessions, exploded planets are not so helpful for funding a rebellion). Some were just farmers from planets far off the beaten path (although that path seems to be well traveled nonetheless).