Since the fact that the Caldari find the practice of slavery inefficient economically has been added to PF, it seems that a lot of Caldari players and more generally a lot of players use that as a fact.
I am far from being an economist so I may be mistaken here, but I do not really understand what makes them believe so. How is a slave less efficient than a paid worker ? I say, it can be less efficient, but it can also be more efficient. Why would we still be using slavery in a lot of countries IRL if that was not efficient ? Why would the previous ages, from Antiquity to XIXth century, resort to it as well, and so widely ? Religion is not the only factor at play, and has not even been considered by some civilizations still widely using it.
I have rarely seen the argument that slaves do not participate in the market since they do not have the power to consume products and thus, do not take part in the global economy. But they still have to be paid for their living, like any worker, by their masters. Their masters consume for them. Some might say that slaves barely need a couch and a few bits of food so that's not much compared to the needs of a paid worker. And yet, a lot of paid workers do not have lives more comfortable than slaves themselves, so their buying power is not really better. And we also have rich slaves, or slaves living in luxury, in the equation, that may account for a lot of money like any rich worker does.
But when you want to be efficient as an employer, you generally don't pay your average base worker much, the same way low end slaves are only afforded the bare minimum to live. Honestly, I have a hard time seeing the difference in terms of efficiency.
I would argue that it's even more efficient to have slaves (like in Antiquity) when you just need basic manpower. If you need more manpower because your own is limited in number, you go invade your neighbors and abduct what you need.
So, yes, I am a little confused about that PF bit.