Retirement is a null concept except for corporate employees - who are going to face it whether they like it or not.
Chinese cities have plenty of women - its the rural areas where you find schools with 30 boys to every girl. Women don't want to get married to peasant farmers, and they leave for the cities as soon as they are able. And having a girl is not considered a family tragedy in the cities the way it is in the farming villages.
The lists left off Chongqing, which is already the biggest city in China at over 30 million people - it's shown on the first map.
There was a Slate article, I think, where the person reviewed the Foxcomm factories where smartphones were made and all those suicides had occurred. The writer said it was the second most tragic thing he’d seen in China, the first of which was Chinese agriculture.
The writer then agreed that the girls were there by choice, because the factory protected them from the elements, had air conditioning, they had opportunities for advancement like learning English and quality control, and they earned two to three times as much as fathers working on the farm. It was horrific to Western sensibilities, but the factory was better than the farm for them - and made them more economically valuable than their brothers.