Well, lets see, when they give birth, you'd presume they don't have insurance, so they'd be paying the hospital for it's services, they also pay for anything they need, airline tickets, transport, food etc. Then they head back to China until the kids need schooling, (I presume, as the article doesn't actually say if any of the kids come back) so they come and live with someone, or their parents come with them, either way these are wealthy families, so it's fair to assume they'd pay taxes and rent, or some such. Then the kids'd get jobs in America, and more than likely become productive citizens. So it actually seems that these kiddies would be less of a strain on the economy than many poor families who reside in California, and are stuck in generational poverty.