During the first wave of the COVID-19 pandemic, Shanghai implemented lockdown measures to stop transmission of the virus. Over 26 million residents, including 0.8 million children aged 3-6, were confined at home. This study leveraged a city-wide cohort of preschool children - the Shanghai...

During the first wave of the COVID-19 pandemic, Shanghai implemented lockdown measures to stop transmission of the virus. Over 26 million residents, including 0.8 million children aged 3-6, were confined at home. This study leveraged a city-wide cohort of preschool children - the Shanghai...

In China, the male-biased sex ratio has increased significantly. Because the one-child policy only applied to the Han Chinese but not to minorities, this unique affirmative policy allows us to identify the causal effect of the one-child policy on the increase in sex ratios by a...