The article attributes the difference to the following, cited from a report on gender equality prepared by the UN Development Programme (UNDP):
Sex-selective abortion, infanticide, and death from health and nutritional neglect in Asia have left 96 million missing women... and the numbers seem to be increasing in absolute terms.
Such differences must have social and geopolitical implications in the years ahead, One could speculate on increased levels of male homosexuality, military adventurism, and sexual emigration not unlike the economic emigration which is prevalent today.