Insights into the causes of Japan's prolonged and sharp fall in total fertility rate come from comparing Japan with France. The two countries share dirigiste administrative approaches, family policy reform undertaken under the auspices of pragmatic right wing parties and justified on pronatalist grounds, and involvement of demographic experts in crafting and shepherding such policies. But the countries differ with respect to their total fertility rates (France 1.98, Japan 1.29) and the effectiveness of their family policies. Thus comparing them can help identify areas of divergence that might explain these differences and assist in the project of theory building. Several salient explanations are rooted in Japan's labor market: it exacts high opportunity costs from parents who interrupt their careers to raise children, keeps ideal workers from having much time for their families, assumes and reinforces a traditional gender ideology, and hires few young workers into good jobs.