And the data shows that both sexes engage in hypergamy. Men marry up in education. Men marry up in beauty. Women marry up in income but not by a lot.

Data is frequently collected with some kind of bias.

Better data with possible bias than definitively bias with no data.

> Data is frequently collected with some kind of bias.

you can't look at electrons without some sort of bias; such is the nature of all research.

however "data is biased", and the implied "statistics are racist / classist / sexist" etc., is most often used by those who don't want to see what the data lays out, and have no other way to discredit it.