Whatever the social and political privileges or status associated with plantership and slaveowning, and we shall see that these were considerable, the business of sugar making was just that, a business. Engenhos and their associated canefields were operated as enterprises, responsive to gain and loss and sensitive to the vagaries of the marketplace. The essential questions we must ask are those the planters asked themselves: What did it cost to set up a sugar mill? From whom could the initial capital be obtained? What was the proper and most profitable mix of productive factors? What did it cost to operate each year, and what was the return on investment? These seem to be rather simple queries, matters of simple accounting, but herein lies the problem. The material needed to answer many of these questions does not exist. Individual estate records are, with a few notable exceptions, lacking. Notarial registers, though more numerous, are scattered, fragmentary, and often silent on important issues. Finally, as a general problem, accounting practices in the period under study consistently mixed current expenses with capital-stock purchases.