Why Have Interracial Marriages Shot Up Since 1997?

Alex Tabarrok pointed today to a paper that caught my eye. In it, the authors offer an explanation for why interracial marriages, which had been increasing at a steady rate for decades, suddenly accelerated in the mid-90s. Their answer: the rise of online dating played a big role.

The reasons for this are a little complicated, and you can read the paper if you’re interested. However, here’s the basic chart that motivates the analysis. It shows the percentage of interracial marriages among newlyweds:

This is interesting, and I don’t really have any special reason to doubt the online-dating hypothesis. But there’s an odd thing: the trendline accelerates first in the mid-90s, and then accelerates again around 2007. (The red line is my eyeball trendline.) So does that mean online dating also accelerated in 2007? It turns out the answer is no:

At the very moment that online dating plateaued among hetero couples, the growth rate of interracial marriages took a big jump, from 0.35 percent per year to 0.58 percent per year. This doesn’t fit the online-dating model.

So either it’s wrong or it’s incomplete. If it’s incomplete, it means something happened around 2007 in addition to online dating that caused a big jump in the number of interracial marriages. What do you suppose it could be? An Obama effect? A Facebook effect? Something else?