@Atulya Mishra Well, people with dysgenic characteristics (low IQ, serious inheritable diseases, etc.) shouldn't be birthing the next generations of society.
I am not going with the low IQ business but some people with inheritable diseases may choose not to have kids as is their right. IQ is far to fragile a marker to use. Can't have kids forever because they took a test after a kegger.
People who belong from higher socio-economic backgrounds should be encouraged to have more kids by the state via incentivization.
They already are in every sense of the word. Think about it. The issues that can make some people avoid having children such as the high cost of labor and delivery, health insurance and childcare are of little concern to the well to do.
Let's face it. The US has created a nearly hostile environment into which a person other than the wealthy might have a child. Rentals of multiple bedroom apartments/houses are sky high for example. A quick check of my local rental market shows that the extra bedroom required for a child can add a week's pay to a low wage worker's monthly bill just by itself. Then health care, day care, dental care, clothing, food, diapers, etc. It is no wonder that people are not having these little economic disasters.