1.) Economic mobility rarely means that someone from the bottom goes to the top, it usually is a one quintile shift if it occurs at all. -snip-
There are quite a few athletes that make the huge jump every year. About 225 are drafted out of college each year and their base salary plus signing bonus, roster bonus, and LTBE earnings place them in top 1% of earners. There's also supplemental draft etc.
There are also other sports to add to that.
You've got emerging musicians who'll go from nowhere to top 1%. See rappers etc.
You've got people entering the workforce who'll make it. A friend of my son graduated and landed a part on a TV series. He went from low to top 1%. Every year somebody new, actually quite a few, will pop up on TV (cable news or series) or star in a movie.
You've got lawyers (and perhaps their client) who hit it big. See John Edwards.
Some ivy league college kids come from wealthy parents and will make the big bucks, but some are from poorer families and attend on scholarships. Some of them will make the big bucks right away.
Somebody will come from nowhere with a new website.
I hear some people who started medical pot stores are making it big. or have until they were busted.
Some young chef will get famous and make the big bucks.
Some will make it in (commissioned) sales. Some in construction once they get that 1st decent/good contract.
There are many ways to make it straight to the top. The 'safe route' isn't usually one of them, though. Graduate college with a degree in management and become an employee - not ever likely to make it quickly to the top. Same for most other employees.
Then there's a whooooole lot of ways to fall from the top.
IMO, the only ones we need to concern ourselves with are those who merely inherent it. But most of the top earners aren't in that class.
Fern