Could it be that by being more picky, we give ourselves a better chance of staying together?
EDIT: I found a more recent one with a relative rate vs. marriages: http://www.telegraph.co.uk/news/uknews/12011714/Divorce-rate...
It may be that, as the article suggests, the decrease in % divorce rates has dropped partly due to the increase in social acceptability of cohabitation, allowing couples to try it out before getting married.
Nevertheless, taking simply divorce rates into account, the situation has improved from 20 years ago.
So have marriage rates - perhaps those who DO get married these days, really mean it.
[1] http://www.theguardian.com/news/datablog/2010/feb/11/marriag... I know the article is a bit old, the trend is still visible though.
Then later as they achieve temporary and then permanent residency the marriage can be used to apply for visa for the spouse.
I have met a few international student couples who marry at 20 or 21, and one of them drops out, for this advantage.
And since they're living pay check to pay check anyway, it's not risky for either of them.
http://m.huffpost.com/us/entry/divorce-cohabitation-stud_n_4...