This is very much true in Russia, where unemployed young people often ride A-class cars or own expensive flats. They are not taxed because their declared income

This is very much true in Russia, where unemployed young people often ride A-class cars or own expensive flats. They are not taxed because their declared income is untaxed gifts. Taxes proportional to value of property balances theese extremes nicely. Unfortunately, not feasible in current russian political climate.