I was planning on writing a long response to assessing the reactions, but given the things on my plate, I have to put it off for a while. An interesting fact came up in the course of my research, though. A commenter by the name of Jamby pointed me to the Spanish system of polo and vandala, and not familiar with those terms, I looked them up.
Here's what I found, an excerpt from a text entitled From Datus Descended, the second chapter of the book The Pampangans by Prof. John Larkin.
Observing the changes in native society during the 194 years of Spanish control from 1571 to 1765, one cannot fail to note their continuity with pre-Spanish patterns or their slow evolution. This gradual adjustment of the Pampangs to the new regime over the course of nearly two centuries was possible because, the Spanish, deeply involved in the galleon trade, brought no social or economic revolution and were more than content to allow native political power to remain with the old ruling class. The province was merely an outpost of an empire which had already begun to stagnate in a near-medieval framework, and Spain, suffering from limited resources and vision, simply did not possess the personnel to plan a new course of development for Pampanga or to administer it properly. To convert the natives to Catholicism and have them remain loyal to the government in Manila was sufficient. The Pampangans expressed loyalty by supplying rice, lumber, and soldiers for the disposition of the colonial establishment and, once these obligations had been fulfilled, were left free to manage their domestic affairs.
This, I believe, merits further inquiry. I think it supports my supposition regarding caste systems.
But wait! It gets more interesting:
Pampanga was subject to three different taxes in the seventeenth century: the polo, the vandala, and the head tax (tribute). The polo was a system of corvée used primarily to build and maintain the Spanish defense fleet and harbor installations. Pampanga supplied woodcutters, shipbuilders, and various other laborers in fulfillment of the polo. The vandala was in essence a tax exaction of rice to feed the Spanish army and navy. Both the polo and the vandala were imposed extensively during the Dutch wars from 1608 but less and less frequently thereafter. There was no such abatement of the head tax because Manila continued to need rice and the head tax, usually paid in rice, was the city's main source of supply. In addition, there were continual demands for lumber. In 1707, for example, when the seminary of St. Clement was established in Manila, the Pampangans were called upon to supply the lumber. Moreover, many Manila galleons of the seventeenth and eighteenth centuries were also constructed of Pampangan lumber.
Only once did anything happen to mar the Pampangans' record of loyal and valuable service to the Spanish up to 1896. In 1660 one group of woodcutters protested the polo, but a brief display of force by the Spaniards, government promises of amelioration, and the lack of support from most Pampangan leaders ended the unrest without a single battle or death. The Pampangan chief most instrumental in suppressing the woodcutters' revolt, Don Juan Macapagal, earned Spanish praise and trust and was called by them to lead (as Master of the Camp) a Pampangan contingent against the threatened invasion of the Chinese pirate Koxinga in 1662. Later he was awarded an encomienda by the king for his long and faithful service.
What do you think?