@Hrothbern did you have any more insight to the source and calculations of the numbers in that graph? I'm not hoping for much but it would be intreresting to know what you know?
Had no real time for something coherent here. I will do that when more time.
Bit here some bits for you already.
There are many sources on wealth. I browse through most of it that is better than fluff. Credit Suisse doing it consequent over some time now (more chance on consistentency methods over time).
That map is from the wiki on median and mean wealth. (that rate interesting because it shows how effective the inequality was per year to pump money upward)
Here the wiki list of that rate. And you can see that the US has a far higher rate (lmost 7) than many rich EU countries: a lower median and a higher mean.
https://en.wikipedia.org/wiki/List_of_countries_by_wealth_per_adult
Numbers there are based on Credit Suisse. Latest 2018 report here:
https://www.credit-suisse.com/media...ch-institute/global-wealth-report-2018-en.pdf
Now... on that real estate
Not every country has the same percentage of houses owned per household.
Normally the higher that % the more adults have benefitted from real estate price increases (typical higher than inflation, and typical more higher than real wage increases).
=> high house ownership lowers the rate between mean/median wealth per adult.
A side factor in some countries important is the marginal price increase effect on houses if there are not enough houses for the population.
For example here in NL there are strict rules where and how to build houses (we have an extreme high population density). This has led together with more divorces, immigration to much pressure on the housing market prices for ordinary houses. With 70% or so of our households owning house, everybody who had a house saw its wealth increasing substantially.
=> a higher effect on the total wealth distribution of real estate compared to other kinds of wealth. (and a moderate mean/median wealth rate).
On the flipside of that: IF 1 million or so Dutch people would emigrate suddenly to another country, the house prices would go down with I guess with 30% at least in that new balance, and reduce median wealth more than mean wealth, and the now very low mean/median rate of 2.2 would increase somewhat (but stay low). Do note that when someone owns a house of 300,000 and has still 200,000 to pay, a price decrease of 30% means his wealth is reduced from 100,000 to 10,000.
Here that % owned houses per household. (Greece has for example 75% and Germany very low with 50%)
https://en.wikipedia.org/wiki/List_of_countries_by_home_ownership_rate
Add for Germany on top that the housing market is not really "mature" in the commercial sense that it is really governed by best selling price => all house prices in more rural reas are "undervalued".
For Germany with a very high mean/median rate of 6 the story could be that much of that 35,000 Euro is not wealth of private house owners (underway with having more house value than remaining mortgage) but of savings by the German households living in rented houses. German cultural mentality (traditional) is to save.
(as a side note: the fiscal policy multiplier as govt counter for economical dips will be low in Germany for actions that benefit median Germans, because they will not spend much, and just add to their savings).
Very important in that wealth accumulation is how much of that is coming from existing wealth and from income (inequality).
Wealth 2018 = wealth growth from (saved) income 2017 + ordinary housing wealth growth from ordinary housing wealth 2017 + other wealth growth from other wealth 2017
On that inequality here below a fair summary article for Europe/OECD showing Gini from disposable income
Gini disposable income = gini market income + redistribution effect tax system + redistribution social benefits (like unemployment money, rent aid, health services, etc, etc, etc)
One factor in that standard Gini is missing and that is income from informal economy. Those percentages are low in US, UK, Nordic, but are 10-20% in Southern Europe countries and easily round 30-50% in Latin America countries and 50% in Africa etc.
When those percentages are higher, most of that is to the benefit and inside the lower income groups. (and the rest is money extraction to the corrupted and the bigger wealth)
=> If you add that informal income to the gini, the south european countries will be more equal (have lower gini) and wealth accumulation is better understood on the lower income range.
(the other thing that gini does not adjust as potential gini of the cultural-political structure of a country is adjust for the currentr level of unemployment)
=> as clear example
When the US has a high gini with low informal economy and low unemployment, that high reported gini matches the high intrinsic gini of the US.
When for example Greece has a relatively high gini for the EU, but I adjust for the informal economy and the high unemployment, Greece has an intrinsic gini that is not that much higher as Netherlands, Nordic countries, Germany.
https://www.oecd.org/els/soc/cope-divide-europe-2017-background-report.pdf
On page 10 wealth distribution.