Unpaid Caregiving and Divergent Salary Trajectories In Midlife: A Longitudinal Growth Mixture Modeling Study

Background and Purpose:
As population aging increases the demand for informal care, a growing number of midlife adults balance unpaid caregiving with labor force participation. While prior research documents short-term employment disruptions among caregivers, less is known about how caregiving is associated with long-term salary trajectories. Guided by human capital theory and life-course stratification perspectives, this study examines heterogeneous salary trajectories among U.S. workers and evaluates how caregiving roles and contexts are associated with differential long-term earnings patterns.

Methods:
This study uses eight waves (2008–2022) of the National Longitudinal Survey of Youth 1979, focusing on midlife adults (N = 3,973). Growth mixture modeling (GMM) was employed to identify latent salary trajectory classes over time. Multinomial logistic regression was then used to examine how caregiving context (in-home vs. out-of-home), caregiving intensity, age, gender, and marital status were associated with class membership. Salary was log-transformed, and models were selected based on fit indices (AIC, BIC, entropy) and interpretability.

Results:
A four-class solution best fit the data, identifying distinct salary trajectories: high-stable, delayed-drop, early-drop, and low-rising. Results indicate substantial heterogeneity in earnings patterns among caregivers. Providing in-home caregiving and experiencing sustained care needs were strongly associated with membership in the early-drop and low-rising trajectories, suggesting disruptions to wage accumulation during midlife. Out-of-home caregiving was also associated with declining salary trajectories, though to a lesser extent. Marital status played a protective role: being married was associated with higher likelihood of belonging to the high-stable trajectory, whereas being widowed was associated with increased likelihood of early salary decline. Older age was consistently associated with membership in declining trajectory groups.

Conclusion and Implications:
Findings demonstrate that unpaid caregiving is associated with divergent long-term salary trajectories rather than uniform economic penalties. Caregiving responsibilities, particularly those requiring in-home or sustained involvement, are linked to disrupted wage growth and potential cumulative disadvantage in midlife. These results highlight the need for targeted workplace policies, including flexible scheduling, caregiver supports, and income protections. For social work practice and policy, the findings underscore the importance of recognizing caregiving as a structural labor issue with long-term economic consequences, calling for interventions that address both immediate caregiving demands and their lasting impacts on financial well-being.