Interesting. In Russian and Polish this kind of phrase is quite common. In German it's not common, and I would consider it bad style. How about English?

"Eight times poorer" is improper English and makes no sense, but is a very common usage. Most of the time multipliers are written when they should have used reciprocals. My only explanation is that it is more dramatic to say "eight" and "poor" in the sentence than "1/8" (hey, that looks like math, math is hard) and "rich" (they are emphasizing the poorness of the poor, not the richness of the rich).

Proper English, as I understand it, would be to say "they were 1/8 as rich" or "they have only 12% as much wealth", but that is much less dramatic.