Honestly, very little IMHO. Take a look at the blurb at the top of this page [1]. "Cost of living in Japan is 16.88% higher than in United States (aggregate da

Honestly, very little IMHO. Take a look at the blurb at the top of this page [1]. "Cost of living in Japan is 16.88% higher than in United States (aggregate data for all cities, rent is not taken into account). Rent in Japan is 31.95% lower than in United States (average data for all cities)." This correlates pretty well with my experience. Even in Tokyo, prices are not that high (compared to London or Sydney, for instance -- and nowhere near SV). Because there is a good train service, it's also very reasonable to live in the countryside and commute to work. Even if you work in Tokyo, it is very easy to live in Chiba , Saitama or Kanagawa. Admittedly I really live in the countryside but my monthly rent is just 66,000 yen ($591 US as of today) per month for a modern 2 bedroom apartment with galley kitchen, living room, balcony and 2 parking spaces. Used 3 bedroom houses routinely go for $100-150K in this area, with fixer-uppers being under $100K. Most of Japan is not expensive for rent. Cost of living is higher than the US and salaries are lower, but people tend to be more frugal too. Also, children often live with their parents until they get married (late 20's to early 30's). IMHO, the reason for the low fertility is that young men in Japan have to get their career going and work very hard right out of school. Women, on the other hand tend not to have those kinds of career aspirations (for better or for worse). They usually intend to get married and have kids. Young women tend to view their 20's as their time to be free and they often travel (a lot!). Usually young women are fairly well off because they live with their parents. Even though they tend to contribute to the family income, the shared cost of living is quite a bit lower than if they lived alone. They work in factories, or in offices and don't really have a lot of responsibilities. They tend to put off getting married as long as possible because after they are married, they often have to quit their jobs and concentrate on running the household. The average age of marriage in Japan is 30.1 years old, according to Wikipedia. The average age in the US is 28.2. Young people in Japan also don't tend to live together before marriage, while US couples tend to live together for 2-4 years before getting married (I couldn't get good stats, but it seems like 1-2 years before getting engaged and 1-2 years after getting engaged based on various google searches). Because people in Japan do not live together before marriage, they are less likely to have children before marriage. This resource [3] shows an interesting statistic: The average woman has their first child at 30.7 years old, while the average US woman has their first child at 26.3 years old. In my mind, this is really the difference in fertility rates. Women in Japan are trying to put off getting married and having a family, while Americans are not. [1] - https://www.numbeo.com/cost-of-living/country_result.jsp?country=Japan https://www.numbeo.com/cost-of-living/country_result.jsp?cou... [2] - https://en.wikipedia.org/wiki/List_of_countries_by_age_at_first_marriage#Asia https://en.wikipedia.org/wiki/List_of_countries_by_age_at_fi... [3] - https://www.thebalance.com/what-is-the-average-age-to-have-a-baby-in-the-u-s-4582455 https://www.thebalance.com/what-is-the-average-age-to-have-a...