It is important to distinguish several factors, of course. Note the fact that trends occur over time. The fact that 25% of women in marriages make more money than their husbands overall is interesting. It would be more interesting to further divide for marriages contracted in the last however many years. We should expect to see a gradual rise, so that marriages contracted 30 years ago have a much smaller percentage than marriages contracted within the last five years (it would also be interesting to note if same sex couples are excluded from the tally -- but they are such a small percentage relative to the population as a whole and such a recent phenomena I would not expect it to impact the data much). other comparisons and trends can likewise be pulled out.