Determinants Of Fertility In The United States

Author

Munerah Alghamlas, Wayne State University

Access Type

WSU Access

Date of Award

January 2024

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Economics

First Advisor

Stephen Spurr

Abstract

This study analyzes the determinants of fertility among women aged 15–50 in the United States, using data from the June Current Population Survey (CPS) for 2010 and 2016. The study aims to understand how various socioeconomic and demographic factors, including family income, education level, female share of household earnings, marital status, age, race, and ethnicity, influence the likelihood of having children and the total number of children ever born. We employ three different regression models—Logit regression, zero-inflated Poisson regression, and Poisson regression—to examine these relationships and identify any significant changes in fertility determinants over the six years. For the ANYBORN outcome, we use a Logit regression to estimate how the probability of having at least one child is affected by determinants of fertility. Our second and third regressions use zero-inflated Poisson regression and Poisson regression to analyze the TOTBORN outcome, which is the number of total births a female has, using the same independent variables. Our main findings are as follows: First, the logistic regression models for 2010 and 2016 revealed that females with no high school diploma were more likely to have at least one child. Women with a high school diploma also showed an increased likelihood. The coefficients were positive for females with some college education but decreased slightly over time. Conversely, females with graduate degrees were less likely to have children. Family income negatively impacted the probability of having children, while the female shares of household earnings increased the likelihood, though its effect decreased over time. Marital status remained a strong predictor, with married females more likely to have children while never-married females were less likely. Age significantly influenced childbirth probability, with a stronger impact observed in 2010 compared to 2016. Racial and ethnic differences indicated that Black non-Hispanic and Hispanic foreign-born females had increased probabilities of having children, while White non-Hispanic and non-Hispanic foreign-born females showed decreased probabilities, though the negative impact lessened over time. These findings suggest evolving societal and economic factors influencing fertility decisions between 2010 and 2016. Second, both the zero-inflated Poisson regression and Poisson regression analyses for 2010 and 2016 reveal significant associations between various demographic factors and the number of total births for females. Key findings include a positive relationship between lower educational attainment and higher birth rates, while higher education is associated with lower birth rates. Family income negatively impacted birth rates, and the female share of household income positively influenced birth rates, though this influence slightly decreased over time. Marital status showed substantial effects, with married females having higher birth rates and never-married females having lower birth rates. Age significantly affected birth rates, with its influence declining over time. Ethnicity and birthplace also played a role, with White non-Hispanic US-born females consistently having lower birth rates and Black non-Hispanic US-born females having higher rates, although these effects declined over time. These findings highlight evolving relationships between demographic factors and fertility, reflecting broader socio-economic shifts and changing family planning behaviors over the years.

Recommended Citation

Alghamlas, Munerah, "Determinants Of Fertility In The United States" (2024). Wayne State University Dissertations. 4111.
https://digitalcommons.wayne.edu/oa_dissertations/4111