Our comprehensive review and meta- analysis of these experiments find suggestive evidence of health benefits associated with investments in early life , income support , and health insurance interventions .
Housing and neighborhood trials had no effect on the outcomes included in the meta-analyses .
A positive effect of the trial on its primary socioeconomic outcome was associated with higher odds of reporting health improvements .
Early life , income , and health insurance interventions have the potential to improve health .
Policy Points Social policies might not only improve economic well-being , but also health .
Health policy experts have therefore advocated for investments in social policies both to improve population health and potentially reduce health system costs .
Since the 1960s , a large number of social policies have been experimentally evaluated in the United States .
Some of these experiments include health outcomes , providing a unique opportunity to inform evidence -based policymaking .
CONTEXT Insurers and health care providers are investing heavily in nonmedical social interventions in an effort to improve health and potentially reduce health care costs .
Evaluating the health effects of social interventions
Is no evidence better than any evidence when controlled studies are unethical ? Rigorous evidence on the health effects of social interventions is scarce1 2 despite calls for more evidence from r and omised studies .3 One reason for the lack of such experimental research on social interventions may be the perception among research ers , policymakers , and others that r and omised design s belong to the biomedical world and that their application to social interventions is both unethical and simplistic.4 Applying experimental design s to social interventions may be problematic but is not always impossible and is a desirable alternative to uncontrolled experimentation.3 However , even when r and omised design s have been used to evaluate social interventions , opportunities to incorporate health measures have often been missed.5 For example , income supplementation is thought to be a key part of reducing health inequalities,6 but rigorous evidence to support this is lacking because most r and omised controlled trials of income supplementation have not included health measures .5 Current moves to increase uptake of benefits offer new opportunities to establish the effects of income supplements on health . In attempting to design such a study , however , we found that r and omised or other controlled trials were difficult to justify ethically , and our eventual design was rejected by funders . # # # # Box 1 Attendance allowance A pilot study carried out by one of us ( RH ) showed substantial health gains  among elderly people after receipt of attendance allowance . We therefore decided to pursue a full scale study of the health effects of income supplementation .
Our comprehensive review and meta- analysis of these experiments find suggestive evidence of health benefits associated with investments in early life , income support , and health insurance interventions .
Housing and neighborhood trials had no effect on the outcomes included in the meta-analyses .
A positive effect of the trial on its primary socioeconomic outcome was associated with higher odds of reporting health improvements .
Early life , income , and health insurance interventions have the potential to improve health .
Policy Points Social policies might not only improve economic well-being , but also health .
Health policy experts have therefore advocated for investments in social policies both to improve population health and potentially reduce health system costs .
Since the 1960s , a large number of social policies have been experimentally evaluated in the United States .
Some of these experiments include health outcomes , providing a unique opportunity to inform evidence -based policymaking .
CONTEXT Insurers and health care providers are investing heavily in nonmedical social interventions in an effort to improve health and potentially reduce health care costs .