I don't know what the Welfare system's like in the US, but in the UK the more kids they have the more money they get, the bigger the freeby house etc. Just now the maternity units there are failing - there's been a huge jump in the birthrate between 22% in London and 63% in Corby (also big jump in immigrant numbers in Corby - coincidence?). If they restricted welfare payments to two kids I bet the birthrate would fall straight away.