As the plantation complex moved out of the Mediterranean, bound for the Caribbean, it changed. First of all, the scale of operations in the Mediterranean was small, and the relative weight of the complex in the Mediterranean economy was also small. In addition, the Mediterranean slave trade of the Middle Ages mainly supplied service slaves destined to be soldiers, domestic servants, concubines, harem guards, and the like — occupations of particular trust or intimacy that were better done by strangers than by people from within the Mediterranean society. The Mediterranean slave trade supplied a few plantation workers as well, but the Atlantic slave trade dealt mainly in agricultural labor. On Mediterranean plantations, some workers were slaves, but not all. In the later plantations at the height of the system, all were slaves. Indeed, most of the drivers and foremen in the sugar house – definitely management, even at a low level — were slaves as well.

The demography of the Mediterranean and Atlantic slave trades also appears to have been different. Deaths exceeded births on the West Indian plantations from the sixteenth century on, and the slave trade supplied the deficit. The migration of the slaves was not, therefore, a one-time event. The plantations needed a continuous supply of a new labor, if only to remain the same size. Growth required still more. We know less about the demography of Mediterranean slavery, but from what is known about the epidemiology and environment, after the first generation a net natural decrease in plantation populations would not be expected.