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Sweden: Higher Income Linked with More Children

Study: The relationship between life-course accumulated income and childbearing of Swedish men and women born 1940–70

The long-held belief that poorer individuals have more children is being challenged by recent findings in Sweden. Martin Kolk’s study presents a paradigm shift, indicating a positive association between higher income and fertility rates in Sweden. This development could potentially reverse the 20th-century income-fertility relationship as we move through the 21st century.

Background: A Centuries-Old Debate

For centuries, social scientists and statisticians have pondered whether wealth impacts family size. Traditionally, it was assumed that lower-income individuals had larger families. However, Kolk’s 2022 research in Sweden contradicts this notion, suggesting a significant shift in this dynamic.

Methodology: Assessing Lifetime Earnings and Fertility

Kolk analyzed Swedish taxation registers, focusing on Swedish-born individuals. By evaluating incomes over working ages and separating data by gender, Kolk bypassed the complexities of short-term income and childbearing interrelations. This approach allowed for a clear view of lifetime earnings and their correlation with family size.

  • Men: A consistent trend across all cohorts shows that higher-income men tend to have more children.
  • Women: The pattern is more complex. Initially, low-income women (often homemakers) had more children. But in more recent cohorts, this trend reverses, with higher-income women having more children. This relationship, however, plateaus at a certain income level, indicating similar fertility rates among upper-income women.

Key Insights: The Role of Disposable Income

Both men and women with 2-4 children have the highest lifetime incomes. However, income slightly decreases for those with very large families (5 or more children). The study also highlights the significant role of disposable income, including government benefits, in influencing these trends.

The shift in Sweden suggests that the traditional negative correlation between income and fertility may be a thing of the past. This change could be driven by evolving cultural values and the economic reality that raising children is becoming increasingly expensive. Sweden’s welfare support for childrearing and female employment might condition these findings, but the trend could soon become global, manifesting in various forms:

  1. A direct positive correlation between individual income and fertility.
  2. A link between fertility rates and the business cycle.
  3. Higher fertility in wealthier nations compared to less affluent regions.

Bottomline: A New Century, A New Pattern

Kolk’s research points to a significant reversal in fertility trends. What was once a staple of demographic studies – the belief that poverty equates to larger families – may no longer hold, at least in Sweden. This shift could indicate a broader global trend, reshaping our understanding of the complex relationship between income and family size in the 21st century.