China has another very serious demographic problem due to sex-selective abortion and its one-child policy, resulting in a ratio of 120 boys for every 100 girls. It's estimated that the percentage of men in their late 30's who have never married will quintuple by 2030, and this large number of unmarried young men will have a detrimental impact on population growth.
By 2026, both India and China are estimated to have 1.46 billion residents each, but India will start to take 1st place with a growth continuing until 2060, while China's population is expected to decline after 2030.