I can't say that I've ever cared what a man's pure salary is and I'm an engineer. Most men I've dated have made less than I have, and it's no sweat. I don't think women are looking for more money if they are a professional or even the same money, they are looking for capability, understanding of the importance of her job (and content of it) as well as his own, a similar idea of what their life together will be like, and an agreement about what each partner needs. I'm not sure the studies you read were comprehensive enough to find this information.