Background: I find it highly plausible that low parental income causes increased risk of mental disorders. I also think it is extremely important to know whether low parental income causes mental disorders, and to have a good estimate of the effect size.
So I read through this and of course down at the end we get:
"It is important to note that rather than investigating the causal effect of parental income per se, we conceptualised parental income as an indicator for an array of measured and unmeasured monetary and non-monetary indices of family’s social environments that are typically interrelated. As our results indicate, controlling for a range of covariates attenuates the relative risk estimates observed, but such estimates would still only constitute partial adjustments as it would never be possible to control for all relevant correlates, and therefore completely disentangle these non-monetary influences from the direct monetary impact."
The first sentence is true. Dropping the pompous gobbledegook, it says "we don't know if this is a correlation or a causal link". Yeah, that's what I expected.
The second sentence is just bullshit. "it would never be possible to control for all relevant correlates..." - sure, if you do crappy 1980s-style observational research that is all you'll ever get. Meanwhile, for the past, oh, twenty years or more, there have been people doing actual experiments to find out the causal effect of poor people getting more money. I mean, say what you like about Jefffrey Sachs but at least he knew to run an experiment.
How does the medical profession continually get away with this garbage social science? Are they stupid? Do they not understand that this work adds zero value? Or are they just pretending not to know about the alternatives - i.e. they're liars? Which is it? Stupid? Or liars?
Another piece of flagrant dishonesty is their recommendation: "Interventions to mitigate the disadvantages linked with low income, and better opportunities for upward socioeconomic mobility, are needed to reduce social inequality in mental health". OK, so you just admitted that you don't know whether low income causes mental health problems. But now apparently we need to fix low income so as to stop causing mental health problems. Which is it?
If you're a left wing person, God bless you. Now, how about producing some decent social science instead of this worthless garbage?
Edit: here's a review of the causal literature on cash transfers from 2016. It includes an entire chapter on health. Relevant quote:
"All studies included under question one – examining the effects of cash transfers on the selected outcomes – had to use either an experimental design (i.e. randomised control trial (RCT) or cluster-RCT)57 or a quasi-experimental design that relies on a credible control group." (They did allow for diff-in-diff, which isn't perfect, but at least they are talking about causality.)
https://www.odi.org/sites/odi.org.uk/files/resource-document...