Understanding Fertility in an Era of Uncertainty
Fertility dynamics lie at the core of demographic change, influencing population aging, labor markets, and social support systems. The Institute of Experimental Demography has launched a comprehensive research program dedicated to unraveling the complex, often counterintuitive, drivers of contemporary fertility. Moving beyond broad economic indicators, our work employs experimental and quasi-experimental designs to pinpoint causal factors. We investigate how sudden economic downturns, specific welfare policies, evolving workplace norms, and shifting ideas about partnership and parenthood interact to influence individuals' childbearing plans and behaviors. A key finding from our natural experiment analyses is that the relationship between economic conditions and fertility is highly context-dependent; for instance, job insecurity may delay first births but have less effect on higher-order births. Our research aims to build a more granular, life-course-informed model of fertility that accounts for the diverse experiences of different social groups.
Key Research Projects and Findings
One flagship project, 'Family Frontiers', uses a combination of administrative data and targeted surveys to study the impact of localized family policy innovations. By comparing municipalities that introduced generous, flexible parental leave schemes with those that did not, our researchers have isolated significant effects on both the timing of first births and the likelihood of having a second child, particularly among highly educated women. This work directly informs debates on work-family reconciliation.
Another initiative, 'The Fertility Preferences Lab', utilizes survey experiments to understand the gap between intended and actual fertility. We present respondents with randomized vignettes describing different life scenarios (career opportunities, housing stability, partner support) to see how these factors shift their stated childbearing intentions. This method reveals the latent constraints and facilitators that people consider when forming family plans, which are often missed in standard surveys.
We also run a longitudinal bio-demographic study tracking stress biomarkers, relationship quality, and fertility outcomes among couples trying to conceive. This interdisciplinary project seeks to understand the physiological pathways through which psychosocial stress may affect fecundability, offering a new lens on sub-fecundity and reproductive health.
- Project UPTAKE: Evaluates the causal impact of subsidized assisted reproductive technologies (ART) on fertility rates and family composition.
- Gender Equity and Fertility Study: Uses cross-national natural experiments to test whether policies promoting gender equality in housework and childcare boost fertility.
- Digital Narratives Project: Analyzes social media and online forum data to track real-time shifts in societal discourse around childbearing and parenting pressures.
- Immigrant Fertility Adaptation: Employs matching methods to study how fertility trajectories of immigrant groups change in response to specific integration policies.
Redefining 'Family' and Future Directions
Our research explicitly recognizes the diversification of family forms. Studies extend beyond heterosexual married couples to examine fertility desires and outcomes among single parents by choice, LGBTQ+ couples, and people in non-cohabiting partnerships. Experimental survey modules help us measure and understand potential biases in how different family structures are perceived in society and within institutions, which can affect access to services and support. Looking forward, the institute is pioneering the use of agent-based modeling, where simulated 'artificial populations' of individuals with rules derived from our experimental findings allow us to forecast long-term fertility trends under various policy and economic scenarios. This fusion of micro-level causal evidence with macro-level simulation represents the cutting edge of fertility forecasting. By grounding our models in proven causal relationships rather than historic correlations, we aim to provide policymakers with more reliable tools for planning education, healthcare, and pension systems. The ultimate goal of our fertility and family research is to generate knowledge that supports individuals in achieving their reproductive goals and helps societies build resilient, supportive environments for all types of families in the decades to come.