Relative and potential income and fertility

Abstract

The effects of substituting measures of husbands relative and family potential income for the commonly used husbands current income were examined discussing the concepts of potential and relative income and their operationalization reviewing the interrelationships between potential income and its components and using data from a consumer panel study to relate the various measures of income to fertility. Data for the analysis were collected in a panel study of a marriage cohort. Respondents were married in the summer of 1968 in Peoria and Decatur Illinois and resided in the standard metropolitan statistical areas of these 2 cities immediately after marriage. Only couples in which the husband was under age 30 at the time of marriage and in which the combined annual income of both partners was at least $5000 were eligible for inclusion in the panel. The couples were interviewed approximately every 6 months beginning in the fall of 1968. The analysis uses data from the 1st 10 interviews. Much of the income data are taken from 10 interviews which took place in April 1975. Of the original panel of 266 couples 154 nonseparated or divorced couples remained in the panel at the 10th wave. 71% of the respondents want to complete childbearing with a 2-child family. In the 7th year of marriage 92% had at least 1 child and 62% already had at least a 2-child family. Potential family income (Pf) as operationalized here is the income a family would earn if both spouses worked full time. Neither husbands current income nor any of the suggested substitutes--potential family income husbands potential income at age 40 husbands reference group income and husbands relative income--were significantly related to either current fertility which is the number of children after approximately 7 years of marriage to desired family size or to the timing of the 1st birth. Only wifes potential income her actual income and actual family income were significantly related to current fertility. Women with higher actual and potential incomes had fewer children. Only actual family income in 1974 was significantly related to desired family size. Since none of the measures of wifes income were significantly related to desired family size it appears that the relationships to family size after 7 years of marriage resulted from the relationship between the timing of children and wifes working in the early stages of marriage. When current fertility was regressed on the wifes potential income and the husbands or familys income measures the wifes potential income had a significant negative effect on current fertility.