Seeing babies makes people want babies, and as births fall, that pull weakens too. Two economists have built this “empathy channel” into a model of fertility and estimate it can account for 3% to 33% of the fertility decline, with 13.4% as their central figure.
The paper is by Sebastian Galiani of the University of Maryland and Raul A. Sosa of Universidad de San Andrés in Argentina. It was issued in April 2026 as NBER Working Paper 35021.
A feedback loop grounded in biology
The authors start from research in neuroscience, endocrinology and anthropology. Brain imaging shows that infant faces activate the reward circuitry even in women who have never given birth. Contact with infants is tied to oxytocin release, which promotes caregiving, and hands-on care activates similar brain networks in fathers.
They also cite psychology work finding that the emotional pull of seeing and holding babies is about twice as strong as deliberate weighing of costs and benefits in predicting “baby fever.”
Modern life cuts that exposure. Fewer babies are born, young adults live in child-free apartments and workplaces, and childcare happens behind closed doors. The authors note that more religiously observant communities, with dense social ties and highly visible infants, keep higher fertility, the Amish being a clear case.
Births as a public good
Galiani and Sosa embed this in a standard quantity-quality model of family choices, with two groups: a high-exposure group, calibrated to people who attend religious services weekly or more, and everyone else. Each birth raises other adults’ desire for children, but no family accounts for that benefit. Births become a public good that the market underprovides.
The channel is nearly dormant when fertility is high, because exposure is close to saturation. It switches on as fertility falls. In the calibration, a cost shock that would cut fertility by 17.4% on its own produces a 20.1% decline once the feedback loop runs.
How big a baby bonus
The model calls for a per-child subsidy, but the simple textbook correction overshoots by 23% to 32%. Subsidies raise fertility, which raises exposure, which closes part of the gap on its own.
The best target is the group that generates the most externality per dollar spent, which in the model is the smaller high-exposure group, not the group with the largest effect per child. A uniform subsidy still captures more than 98% of the gain from a targeted one.
At the baseline, the optimal subsidy raises welfare by 0.22% in consumption-equivalent terms, about $117 per family per year in the working draft. The authors point to a testable prediction that sets their mechanism apart from conformity models: the channel should grow stronger as fertility falls.
Study Details:
- Title: The Empathy Channel in Fertility
- Authors: Sebastian Galiani, Raul A. Sosa
- Journal: NBER Working Paper No. 35021
- Publication Date: April 2026
- DOI: 10.3386/w35021