I think divorce rates in fact are a good indicator of a communities rate of successful marriages. Another good indication is the domestic violence conviction rate reflected in the local court records or police blotter.
I don’t.
Both of those things have many other factors also involved. Probably you can say a marriage that ended in divorce was unsuccessful, but you can’t really get any more data than that out of it.
And probably we can imagine domestic abuse is not compatible with a successful marriage. But if you think it is a natural corollary of an unhappy marriage, that is very concerning.