JJ, that's a very revealing graph. Ratio of average / median in US is 6.2! In Europe, it's typically 2 or 3. US has an incredibly unequal wealth distribution, which is the root cause of all its problems. The top 1% own more than 1/3 and control almost everything, leaving the rest of US population virtually powerless.
Up to about 1973 US was in line with Europe, then it started changing. The rich started stealing all the money. Top 1% holdings increase, almost on a straight line, from about 10% to 34%. (It's probably even more; that's what they admit to these days.)
Why? What's so different about the US?
This question is very important to all of you, because you don't want the same thing to happen to your countries. IF you know the cause you can prevent it.
And, what happens next in the US? Again this is important to you, considering US military and economic power. It's already very dangerous to the rest of the world, but Europe still feels safe. That will change in a few decades. So it's vitally important to understand what went wrong.
So - what's your guess? What key difference(s) between US and Europe (and the rest of the world) is responsible for this collapse of US society, starting some time after WWII?