In the United States adult children living at home is an increasing trend as well as a source of consternation due to parental conflict and social stigma. Perhaps a bit more surprising is that this trend is increasing all over the developed world from Japan to Europe.

In the United States more 18-34 year-olds are living with parents now (32.1%) than in 1880 (29%) according to census data and a Pew analysis. This increase started in 2000 at 24% with Gen X and increased both before and after the great recession up to 32.1% by 2014. Between 1960 and 2000 there was just a 4 percentage point increase.

There has also been a consistent pattern of American men in the US of living at home more often than women since WWII. That is true in almost all high-income nations.

By comparison, the EUs rate is 48.1% of 18 to 34 year-olds living with parents in 2014. The geographic disparity is stark with eastern and southern Europe reaching levels of 70% and higher. Scandinavia has the lowest rates, the lowest rate for any country in the EU is 18.6% in Denmark. In the EU  21 of the 28  countries had increasing rates of children at home from 2005 to 2014 in part due to the economic crisis that hit from 2009-2013. Like in the US, men are more likely the women to live at home 54.4% to 41.7%.

Unlike Europe and the US, in Canada the increase increase in living-with-parents occurred between 1981 and 1996. In 1981 the rate was 26.9% by 2011 it was 42.5%. The graph below shows 20 to 29 year-olds.

The most economically prosperous cities with high home values have the highest rates of living at home, Toronto 56% and Vancouver 47%, with some neighborhoods topping 75%. Men also are more likely than women to live at home. Marriages and cohabitation have declined about 50% from 1981-2011 in this age group.

In Japan, there has been an explosion in rates even up to 44 years old. Like Canada, the trend started in 1980 when the percentage of 20 to 34 year-olds increased from 29.5% to 42.7% between 1980 and 1995. And increase another 6.2% to 48.9% by 2012. Even 35 to 44 year-olds went from 2.2% in 1980 to 16.1% in 2012. In Australia rates of 18 to 34 year-olds living at home increased from 21% in 1976 to 29% in 2011. Marriage cohabitation rates decreased from 74% to 42% in this time frame. These numbers are quite similar to the US.

Why the rates of living with parents have been going up is not clear, and each person and country has its own pattern. Increasing housing price, parents living in areas with jobs, social norms, gender, and importantly marriage rates all seem to play a part. Industrial development in its early stages as with China today tended to break up families as children moved to the city for work leaving the parents in the rural provinces. Now a global reverse seems to be happening for more advanced economies.

(note the methods and definitions can change from country to country, so the differences are not precisely known)