Consider the following example:
A + B => Y (one A and one B causes one Y) A => 2Z (two A causes one Z)
If you have a data set featuring B, Z, and Y then a regression analysis will yield that Y = 2Z + B, and you would conclude that Z is "a root cause" of Y over B. However, by construction Z has no causal effect on Y, only B does. This is literally the point of "correlation does not imply causation".
Moreover, the white-paper the op-ed author is citing [0] doesn't even have "fatherlessness" as the most correlated variable: it's poverty across the board (and by a lot). Even if your argument was sound it wouldn't be correct.
[0] https://ifstudies.org/ifs-admin/resources/reports/ifs-strong... Tables 2 and 3
By the way, do I read correctly from the regression analysis stats, that "single young men age 15-29" is -negatively- correlated with all categories of crime?
This demo tends to commit the most recorded crimes, which means that they’re getting arrested or murdered. Presumably in an area where lots of crimes are occurring the corresponding increase in arrests and murders leads to lower population counts on the US Census (which I believe was their source of truth on demo stuff).
tl;dr https://xkcd.com/882/ (except it's not even peer-reviewed research it's just some think-tank publishing PDFs online)
There are so many ways that family structure and crime can share a common cause. At the very most obvious, areas with high crime have high arrest rates so will naturally be missing a lot of men. Ditto for murder rates. Moreover, the relationship between low SES and family structure is well studied, and between SES and crime likewise. From this one would expect exactly what is described by the author. The "academic paper" referred to (laundered by) the author is a think-tank white paper (ie. no peer-review) which uses descriptive summaries and correlational analysis to reach the conclusion touted in the byline. Nowhere do they use any kind of quasi-experimental or causal analysis techniques which would merit ID-ing a "root cause". At best they can say what everyone already knows: SES, single parenthood, crime, and decaying social structure exist in a big tangled causal web. The author is playing the eternal op-ed con of turning thin evidence into ironclad moralization.
edit: One more interesting bit of chicanery is that the whitepaper [0] cited by the author didn't even really find what the op-ed title indicates. In the nationwide analysis they found significant correlation between single-family rates and total crime, but its a 5X weaker effect than poverty and wouldn't be significant if you applied Bonferroni correction (which you should if you're going to be using NHST on each variable separately like they are). In both analyses it's really only violent crimes and homicides that signficantly correlate with single-parenthood, and to that result one kind of has to say "duh" (see above about murder and arrests causing single-parent families). In all cases "single parenthood" is basically the weakest predictor, and again they didn't do anything to actually assess the direction of causality.
[0] https://ifstudies.org/ifs-admin/resources/reports/ifs-strong...