Last week China released new census data showing that Chinese families favor sons over daughters. In 2014, according to the data, Chinese women gave birth to 115.9 boys for every 100 girls. (The natural human birth ratio is around 105 boys to every 100 girls.) Skewed gender ratios of this sort date back to the early 1980s, and the impact has been cumulative. China now has 33 million more men than women, tens of millions of whom may never be able to find mates.

The Chinese government has recently attempted to alter this dynamic by loosening its family planning policies. But new research suggests that this well-meaning policy shift could be counter-productive.

China's so-called one-child policy was initiated in the early 1980s with the goal of slowing the country's population growth. According to the prevailing narrative, it also had the effect of skewing the country's gender balance. The policy is said to have encouraged expectant parents who harbored a traditional preference for sons over daughters to seek out ultrasounds and — if a girl was expected — to pursue sex selective abortions. In that sense, Chinese President Xi Jinping's loosening of the one-child policy in Nov. 2013 might reasonably be expected to begin correcting the country's gender imbalance.