I’d love to be told otherwise if this is untrue, but from what I understand the largest causes of birth rate decline in Japan are social, not economic, requirements. People want relationships, but they don’t want the hassle of Japanese dating. For example, as I understand it, as a man asking a woman on a date in Japan would typically entail bringing both your friends and their friends out on the social outing and paying for everyone’s meal. Because of this people don’t want to date because it could mean having to pay for 4-8 people’s meal.

Japan also has a lot of other cultural weird-isms like refusing to buy perfectly functional houses if they are more than 20-30 years old because their traditions expect houses to be torn down and rebuilt in that time frame.

Also I’ve heard that caring for the elderly is expected to be an all or nothing affair. You either bring your elders into your house and take care of them extensively or you do nothing.

Like I said, if someone has more information I’d love some insights, but the impressions I’ve historically have gotten is that their problems are more than economic.