wow very interesting...
I did notice it said it was "corrected for income" which makes sense.
So if you have 10s of ks in the bank, 10k is small fry, but if you have no savings, it's a lot...
Also I liked this:
"Additionally, we find that having high wedding attendance and having a honeymoon (regardless of how much it costs) are generally positively associated with marriage duration"
Which suggests having lots of supportive friends and family that you are close to helps!