It's not just income, it's disposable income + savings rate. If you're in an Asian country like China or Japan you're probably saving 30-40% of your income eve

It's not just income, it's disposable income + savings rate. If you're in an Asian country like China or Japan you're probably saving 30-40% of your income even if you're "middle class". Here in the US it's more like 7%. In the EU, even when incomes are decent, disposable income is often significantly lower than in the US [1] due to higher taxes, more expensive daily services, etc. The combination means that people have less disposable income and spend a smaller portion of that disposable income on frivolous things. [1] https://en.wikipedia.org/wiki/Disposable_household_and_per_capita_income#Median_equivalised_disposable_household_income_(PPP)_$ https://en.wikipedia.org/wiki/Disposable_household_and_per_c...