[_h4xr]

Of course it can be beneficial to slaves. If they're an asset, and the appreciation in that asset's value accrues mostly to the owner, that owner has every incentive to maximize their value.

As Mencius Moldbug (http://unqualified-reservations.blogspot.com/2009/07/why-car...) points out, one modern version of this is the Japanese lifetime employment system. If a company pays 2% on money it borrows, and gets to keep employees for twenty years or more, it can afford to spend years training them without getting any revenue from their work.