Happiness in Slavery: Played with – Imperial law, despite the extreme cultural aversion to slavery, does permit voluntarily contracted indenture as a way to get out from under unrepayable debts without resorting to bankruptcy, and suchlike. It’s not exactly happy – indeed, by local standards, it is ridiculously humiliating – but it’s probably better than most of the alternatives; and most cultural Imperials would see it as infinitely better than default.
(The kicker: with the exception of not being able to quit until the contract term is up, we would find the ghastly state and working conditions of what the Empire calls “indenture” very familiar indeed. We call it employment.)
Averted pretty comprehensively with actual slaves in the darker and more hideously backward parts of the Worlds, though.