Herd's research focuses broadly on aging, policy, health, and inequality. She has two streams of research. One stream examines how social policies affect gender, race, and class inequalities. The second stream focuses on the relationship between social factors and health. She is the principal investigator of the Wisconsin Longitudinal Study, a member of the Board of Overseers of the General Social Survey, a member of the Board of Overseers of the Panel Study of Income Dynamics, and a member of the National Academy of Social Insurance.
Herd co-authored the 2007 book Market Friendly or Family Friendly? The State and Gender Inequality in Old Age with Madonna Harrington Meyer. Herd is author of numerous articles and chapters that have appeared in Social Forces, Gender and Society, Journals of Gerontology, Journal of Health and Social Behavior, and The Gerontologist among others.