When you are counting up the total value being produced in a free labor market, I believe you are implicitly including the part of that value that is captured by the laborers. That is, if I pay you $10 to produce a good worth $20 to me and so two people each end up $10 richer, you are counting that as $20 worth of production. Under this accounting, I agree it would be quite surprising if slavery were efficient.
But surely no slavery advocate was accounting that way? The efficiency seems more doubtful if you only care about a fixed group of people that doesn’t include the people whose slavery/freedom/nonexistence is being decided. From their perspective, isn’t this like arguing that a farmer should spend $20 to produce $10 worth of extra crops, on the grounds that that’s a net gain if you include the $20 of value received by the plants?
When you are counting up the total value being produced in a free labor market, I believe you are implicitly including the part of that value that is captured by the laborers. That is, if I pay you $10 to produce a good worth $20 to me and so two people each end up $10 richer, you are counting that as $20 worth of production. Under this accounting, I agree it would be quite surprising if slavery were efficient.
But surely no slavery advocate was accounting that way? The efficiency seems more doubtful if you only care about a fixed group of people that doesn’t include the people whose slavery/freedom/nonexistence is being decided. From their perspective, isn’t this like arguing that a farmer should spend $20 to produce $10 worth of extra crops, on the grounds that that’s a net gain if you include the $20 of value received by the plants?