How genuine are sub-replacement ideal family sizes in urban China?

Ideal family sizes remain at or above two in most low-fertility settings, but sub-replacement fertility ideals have been reported for urban China. The presence of restrictive family planning policies has led to a debate as to whether such ideals are genuine. This study exploits the ending of the one-child policy and the beginning of a universal two-child policy in October 2015 to investigate whether relaxing the restrictions led to an increase in ideal family size. We apply difference-in-differences and individual-level fixed-effect models to longitudinal data from a near-nationwide survey. For married individuals aged 20-39, relaxing the restrictions from one to two children increased the mean ideal family size by around 0.2 and the proportion who desired two or more children by around 19 percentage points. Findings suggest that although reported ideal family sizes have been reduced by policy restrictions, sub-replacement ideal family sizes in urban China appear to be genuine.