Europe is facing a demographic crisis. Countries like Germany, Spain, and Austria have been seeing declining birth rates for decades, leaving governments puzzled for long-term solutions. Some have opted for child subsidies, but a new study shows that lump sums of money aren’t the magic wand that European governments are looking for. If leaders really want their citizens to have more babies, they need to support mothers.

In a new study (paywall), a German and an American economist draw a few simple conclusions that, put together, show how comprehensive child care policies could really help governments make the case for baby-making.

Matthias Doepke and Fabian Kindermann, from Northwestern University and the University of Bonn in Germany respectively, studied 19 European countries and found that women are more likely to be opposed to having another child if they have already had two children in countries with low fertility rates. From this, the duo posits that couples at odds about having children (when one spouse wants another and the other does not) are less likely to pop another one out; generally speaking, both have to be in agreement in order to bring another life into the world.

Second, they found that—unsurprisingly—the countries where mothers bear most of the burden of childrearing, women are much more likely to not want another child. Using a longitudinal data set of adults in the 19 countries studied called the Generation and Gender Programme (GGP), Doepke and Kindermann analyzed men’s responses to questions about child care—who in your household dresses your children, puts them to bed, helps them with homework—and calculated the average level of their participation in child care across the 19 countries. ”It is precisely in the countries where men do the least amount of work [in raising a child],” they write, “where the fertility rate is the lowest.” On the other hand, France, Belgium, and Norway—which are enjoying relatively high fertility rates—have the highest participation rates of men in child care.

This leaves governments with a difficult task: how to alleviate the child care burden on women. Doepke and Kindermann calculate how well different policies can do that. They found that policies specifically aimed at helping women have and raise children are two times more effective at boosting fertility rates than simple child subsidies, or subsidies given to men. One example the researchers cite is the provision of public child care centers, which would help mothers go back to work and not forgo wages by staying home.

It’s worth nothing that France, Belgium, and Norway—which are enjoying relatively high fertility rates—already have public child care options. France also passed a bill into law in 2014 (pdf) that helped women get back to work after having kids: the Act for Real Equality between Women and Men extended parental leave from six to 12 months—so as long as the additional six months were used by the other spouse.