Our colleague Scott Rothschild, who works in the bowels of the statehouse in Topeka, reported this week about research suggesting unwed births are a leading "cause" of child poverty.

That testimony was given to Gov. Sam Brownback's newly-formed task force on child poverty by Ron Haskins, a senior fellow at the Brookings Institution, a centrist-leaning think tank in Washington, DC.

The governor strongly endorses this theory. In fact, it was just a year ago when he convened a series of conferences on the same subject, including one in Kansas City that featured Robert Rector, a senior fellow at the Heritage Foundation, a conservative-leaning think tank.

This question has broad implications for public schools. There is a well-established link between poverty and a student's chances of success in school. In fact, the single measure that Kansas uses to quantify the number of students "at risk" of failing or dropping out is whether they qualify for free meals under the federal school lunch program.

Using that as a yardstick, it can be argued that every student in a household below 130 percent of the poverty line (or about $30,000 a year for a family of four) costs the state $1,784.67 just in additional education funding. That's the additional "weighting" that schools receive for each at-risk student. (Each "at-risk" student counts as 1.456 students for funding purposes.)

That doesn't even count the additional costs to society for health care, housing, financial support and all the other costs associated with people living in poverty.

It would seem to follow, then, that if being raised in a single-parent home leads to poverty, and if poverty leads increases the risk of failing or dropping out of school, then the marital status of a student's parents should also be a predictor of future academic success.

Furthermore, if the above theory is true - and this is where the Brownback team makes a leap that raises skeptical eyebrows among some people - then government policies that encourage parents to be married and stay married will reduce childhood poverty rates, improve children's chances of success in school and lead everyone to happier and more economically productive lives.

But a review of recent literature shows no clear evidence to support the idea that children of single-parent households are statistically more likely to succeed in school than the children of married couples.

First, let me emphasize I have never believed amateur Google searches are an adequate substitute for "research." What I am reporting here is merely the result of a few searches for studies or writings on the link between marital status and child welfare.

The first comes from the Census Bureau, that vast storehouse of demographic data on just about everything anybody would ever want to know.

In 1998, a team of researchers there wrote a paper, "Poverty, Family Structure, and Child Well-Being: Indicators From the SIPP." (The acronym stands for "Survey of Income and Program Participation.")

One of the ways the authors measured "child well-being" was by looking at whether the child was academically "on track." That is, progressing through school at the age-appropriate grades, not being held back or failing.

They found clear correlations between academic progress and individual variables such as race and ethnicity, the parents' level of education and even what region of the country they were from. (Children in the Northeast and West were more likely to be on track than kids from the South and Midwest.)

But there was a much weaker link between academic progress and the marital status of the parents: 78 percent of children from married couples living together were on track, compared to 72.6 percent for children of parents had been married but one spouse was absent (widowed, divorced or separated), and 71.2 percent for children whose parents were never married.

However, while the authors found correlations between academic progress and certain variables individually, when all the variables were combined to control for one another (a process known as "multi-variate analysis), those correlations disappear.

"When the other aspects of the household are controlled (economic situation, availability of adults, age, education, etc.) designated parents who were never married are not significantly different from those who are married with respect to the current academic status of their children," the authors reported.

Another interesting article - For Love and Money? The Impact of Family Structure on Family Income - challenges the whole notion that single-parenthood "causes" child poverty.

It's interesting because it comes from a project called The Future of Children, a collaborative research effort between Princeton University and the Brookings Institution, home of Ron Hoskins who made that very argument to Gov. Brownback's task force.

That article reviews a number of other research projects on the subject, including three that asked whether single-parent households that are currently in poverty would be any better off, at least economically, by getting married. (At least one author had suggested there simply aren't enough suitable single men out there to lift enough low-income single moms out of poverty to make any difference.)

Using large data sets, the researchers statistically "married off" enough single mothers to return the marriage rate back to where it was in the early 1970s.

The results suggested that increasing the marriage rate would indeed reduce childhood poverty, probably by very significant amounts.

One, however, also suggested the new marriages would pull about 47 percent of poor unwed mothers above the federal poverty line, while the remaining 53 percent would remain in poverty, leading the authors to conclude that government policies promoting full-time employment might be more effective for reducing poverty than policies that promote marriage.