Early on in the USA children were an asset to the farm. Each would do a share of the day to day work that needed done to produce food for the family and to sell for income.
Also children were employed in other family businesses as apprentices and such and thus helped the bottom line of those businesses as well.
But with the change in the work place and fewer and fewer family farms in the USA a child is no longer an asset. (I am talking purely production here not about family values and such) Back in those days having children balanced out financially and even give the family the ability to produce more exponentially with each child added.Not so nowadays.
These days, rare it is that a child adds to the family's monetary bottom line, mainly because of the way society has morphed into a situation where Mom and Dad both work just to keep even with inflation (unless you live a fairly sparse lifestyle or are lucky enough to have one adult with a very high paying job.) Bottom line children "cost" alot now and with ever higher price inflation and the devaluing of the dollar it ain't gonna get better anytime soon!
And yet the state needs the backs of children to dump debts on, to borrow against, to maintain the vote buying/spoils distributing ponzi racket.
Right now we have world wide approached maximum taxation and are squeezing the last delusion that we can tax future non existing children to borrow against.
We are in the final stages of a Madoff economy. Soon there will be a run for the door. First pensioned government minions to gets out, wins.
The grandiose dream of Obama is a symptom of a population that wanted to double it’s bets to get out of the leftist hole that it is in.
We could be entering the end stage of the Roman Empire, where the center ( demographics) collapses. Like the Empire we will take in foreigners to fill the ranks, thinking that if we keep the bureaucratic forms, populate them with foreigners who don’t have the values, have no idea how they were built, that they will carry on our values thought our institutions. This is the leave your business and home to the Mafia theory and it will be just fine.
You talked about children being an asset versus not being an asset from a production viewpoint, but the real issue is from a family values viewpoint. Today's adults tend not to value the child because the child will use resources that the adult wants to use on themselves...this used to be called selfishness.
I would agree that the older children on the farm years ago would be an asset but you are discounting way to much the extra work that the younger children would have been before they became an asset...remember that there were no microwaves, dish washers, clothes washers, disposable diapers, modern furnaces (chop some more wood to keep the baby warm), etc...and a much lower percentage lived long enough to become an asset. And yet people years ago kept having children even with all the extra work...maybe they valued the family over stuff more then we are willing to give them credit for...or maybe they understood that children were a blessing and were willing to except the work that went with the blessing...