Self correlation; parsimony

The study doesn't really say that states with higher taxes are better for kids. What it says is that states which are richer are better for kids. Slight, but important, difference. And poverty rankings have changed little for a century - income has raised everywhere of course, but the overall order has remained constant and would surely be recognizable to Teddy Roosevelt and Woodrow Wilson. Of course some states have experienced booms (and busts) because of their prevalent industries' own fates, but the big picture is still the same, ranking wise. This strongly suggests that the child welfare rankings are also relatively fixed across time. Sooo...

1) That kids are better off in a richer place is true... but trivial (everyone is better off in a richer place). And impossible to translate into any concrete policy.
2) Richer states have also been more to the left since the Progressive Era, generally speaking. So it's no wonder that they would have, by now, significantly higher taxes.
3) It remains not granted to attribute to other variables (all correlated with how rich or poor a state is - including how far it is to the left or right) the welfare of children when income clearly accounts for all of them together with more explanatory parsimony.

a) I suggest that this explains Utah, the outrageous outlier: strongly conservative both socially and economically; has lots of young moms; low taxes... yet a leader in child welfare, but of course! it's also a rich state!

b) I suggest that this phenomenon, in the USA, is no different to the regional patterns of other countries with strong differences in poverty, especially those where such patterns have lasted for decades. The most salient is Italy, of course, but I think it applies to Canada, Mexico, Brazil, Peru, England, Germany, Spain, Nigeria, South Africa, China, Malaysia, Indonesia, Australia and possibly India. Of course, some of these are not federal nations so it isn't possible to compare so many jurisdiction-dependent variables across regions as it is in America. But I keep finding income a better predictor of children well being, over and over.