"disposable income"..........I'm going to guess at this. I notice that Americans are credit card crazy. If they have nothing to do, they go out shopping.....spend money rather than sit home and read a book.
I could be wrong again, but I think Europeans are a lot more careful in how they spend their money. I watch people in supermarkets around here stuff their mega-baskets with junk food, soda, meals in a box (tv dinners). I also watch them take an item off the shelf without even blinking an eye to look at the price. And.....I've stood behind shoppers with all that junk food in their baskets whip out their credit cards to pay the $200-$300 the mini-shopping spree just cost.
How much disposable income can you have when you spend money like that? I believe Europeans are more cultured and spend more time enjoying the Arts instead of going mad at the shopping malls. I'm sure that's part of the reason why the good keyboards go to Europe and the junk boards that just make noise are destined to remain here in the US. Music and quality keyboards are appreciated much more there. Europeans spend their money on quality and get bang for the buck. We have no disposable incomes because we don't manage money as well as Europeans do.