One of the most dramatic changes in American life in the years since World War II involves the way we raise our children.

We used to do it ourselves. Now, convinced we have better things to do, many of us leave the job to others.

Encouraging this flight from parenthood, Sen. Barack Obama of Illinois, the presumptive Democratic presidential nominee, has proposed what he calls his "Zero to Five" plan. It is a collection of programs aimed at getting the government involved in the raising of your children from the moment they are born.

"The first part of my plan focuses on providing quality affordable early childhood education to every child in America," Obama said in a November speech. "As president, I will launch a Children's First Agenda that provides care, learning and support to families with children ages zero to five."

"We'll create Early Learning Grants to help states create a system of high-quality early care and education for all young children and their families," he said. "And we'll help more working parents find a safe, affordable place to leave their children during the day by improving the educational quality of our childcare programs and increasing the childcare tax credit."

This week, Obama upped his ante by vowing to "double funding for after-school programs that help children learn and give parents relief."

Obama, of course, will also continue to defend your "right" to hire a physician to kill your child in utero so you won't have to raise the child at all.

The hard evidence that most American parents now leave at least some of the nurturing of even their youngest children to others has been gathered by the U.S. Department of Labor.

An excellent summary of government data on this issue can be found in "Trends in Labor Force Participation of Married Mothers and Infants," a study by Bureau of Labor Statistics economists Sharon R. Cohany and Emy Sok that was published last year.

"In 1948, only about 17 percent of married mothers were in the labor force," wrote Cohany and Sok. "By 1995, their labor force participation rate had reached 70 percent."

Note that these are "married mothers" -- not single moms, who because of illegitimacy, divorce or a husband's death are forced to work outside the home.

In fact, as of 2005 (the latest year cited by Cohany and Sok), more than 53 percent of married American women with infants (babies less than 1 year old) worked outside the home.

Some of the data points to the conclusion that this phenomenon is driven as much by changes in our values as in changes in our economy.

For example, relative poverty was clearly not the most powerful factor driving married mothers of infants to work outside the home. In fact, those whose husbands earned an income ranking in the lowest 20 percent were the least likely to go to work, Cohany and Sok discovered, while those whose husbands earned an income that ranked in the highest 20 percent were the second least likely to work.

Less than half of these relatively poor and relatively rich mothers with infants worked.

Yet, of the married mothers with infants whose husbands earned an income in the middle 20 percent, 64.4 percent worked outside the home.

Similarly, Cohany and Sok discovered: "The more children a woman has, the less likely she is to be in the labor force." Almost 60 percent of married mothers with infants who had only one child worked. Only 36.6 percent of those who had five or more children worked.

In America today, the rarer child makes a scarcer mom.

It is also telling that while 58.5 percent of native-born mothers with infants worked outside the home, only 35 percent of immigrant mothers with infants did.

Some force in our culture that was not as strong in 1948 as it is today is devaluing traditional family life and the stay-at-home mom.

But this force could be waning. "After a lengthy and dramatic advance," concluded Cohany and Sok, "labor force participation rates for married mothers of infants peaked in 1997 and have been relatively stable since 2000."

Through his plans to increase government funding and control of the rearing of children ages "zero to five," Barack Obama would increase, rather than decrease, the force that drives mothers of infants to leave them in someone else's care. He would also cause a wholly unjust transfer of wealth.

Old-fashioned moms and dads who insist on caring for their own pre-school children will pay for -- but gain no benefit from -- programs that put the government in the business of caring for children whose moms and dads would both rather work outside the home than work raising a child.