Several studies have investigated the association between parental investment and childbearing decisions of adult children. However, studies testing whether changes in parental investment are associated with subsequent changes in fertility intentions over time are lacking. We investigated whether parental investment, measured as contact frequency, emotional closeness, financial support, and childcare, is associated with adult children’s intentions to have a first and a second, or subsequent, child. These associations were studied in four different parent-adult child dyads based on the sex of parents and adult children. We used eight waves from the longitudinal German Family Panel (pairfam) and exploited both between-person and within-person (or fixed-effect) regression models. Between-person associations represent the results across individuals and within-person associations represent an individual’s variation over time (i.e., whether changes in parental investment frequencies are associated with subsequent changes in adult children’s fertility intentions). We found that statistically nonsignificant associations outweighed significant ones. Significant associations were also more often present in the between-person than within-person models. Two of the three significant within-person effects were negative, meaning that when parental investment increased, adult children’s intentions to have a/another child decreased. In between-person models, the parental investment was associated with the childbearing intentions of adult sons rather than those of adult daughters. The present findings indicate that parental investment may not increase adult children’s intentions to have a/another child in Germany.
Translational methods in biostatistics: linear mixed effect regression models of alcohol consumption and HIV disease progression over time
