Joel Martinsen from DANWEI has translated an interview (in Southern Metropolis Weekly) with Wu Si, the writer of a popular social history book The Principle of Blood Payment, commenting on the recent slave labour issue in Shanxi: I wasn't surprised. These things aren't unique to Shanxi. Other provinces may have them as well, and history shows that this sort of thing was prevalent throughout China. In addition, the solutions of the past were basically the same as those today – they rely on supervision of the subordinates by their superiors. If China did not have this sort of thing, then I'd find it strange. Because the core power structure has not changed: it is still an upwardly-responsible pyramid. The exposure of this incident just further corroborates my argument.