Neighborhood green, social support, physical activity, and stress: assessing the cumulative impact.

We estimate the cumulative stress mitigating impact of neighborhood greenness by investigating whether neighborhood green mitigates stress directly, and indirectly by encouraging physical activity and/or fostering social support. Using data from a recent community health survey in Chicago and two-stage instrumental variables regression modeling, we find that different components of neighborhood green play distinct roles in influencing stress. Park spaces are found to indirectly mitigate stress by fostering social support. Overall neighborhood vegetation is found to have direct stress mitigation impact, yet the impact is counteracted by its negative effect on social support. When comparing the effect size, park spaces show a more positive impact on health and well-being than the overall neighborhood vegetation level. Policy makers are recommended to focus on creating structured green spaces with public recreation and socialization opportunities rather than simply conserving green spaces in the neighborhood. Previous studies, as they often investigate the direct impact only and rarely use multiple measures of greenness, may have mis-estimated health benefits of neighborhood green.