As it usually happens in the social “sciences,” it’s very naive to believe that in any of these cases we have anything like solid evidence about the total effect of the programs in question.
This sounds like the fallacy of gray. You can seem sophisticated by saying that it is naive to take any research at face value—that there are always limitations to the studies, and possible unmeasured effects. But there are some cases where the evidence is stronger than others, and where the existence of large unmeasured effects in the opposite direction is less plausible. Paying attention to that evidence is updating.
The particular case of Nurse-Family Partnership looks like one of more strongly supported programs. It has been studied extensively using randomized controlled trials, with data collected on a variety of outcomes (including a follow-up study looking at 19-year-olds who had been through the program as infants). GiveWell named it a top-rated US organization in 2010 (they now say that it is outstanding but lacks room for more funding). Your story about a possible hidden cost does not sound very plausible, and I imagine that some of the studies include data which speak to some of the steps in your story (e.g., whether women who take part end up having more additional children than those who do not).
This sounds like the fallacy of gray. You can seem sophisticated by saying that it is naive to take any research at face value—that there are always limitations to the studies, and possible unmeasured effects. But there are some cases where the evidence is stronger than others, and where the existence of large unmeasured effects in the opposite direction is less plausible. Paying attention to that evidence is updating.
The particular case of Nurse-Family Partnership looks like one of more strongly supported programs. It has been studied extensively using randomized controlled trials, with data collected on a variety of outcomes (including a follow-up study looking at 19-year-olds who had been through the program as infants). GiveWell named it a top-rated US organization in 2010 (they now say that it is outstanding but lacks room for more funding). Your story about a possible hidden cost does not sound very plausible, and I imagine that some of the studies include data which speak to some of the steps in your story (e.g., whether women who take part end up having more additional children than those who do not).