... the basement income to qualify as 'rich' will here be
considered to be $400,000 in annual income that'll come in
regardless of whether anyone in the family is holding a
paying job or not.
From "What are your TRUE chances of getting rich in America?
OR How to get rich in America"[1]
You might also be interested in "The super-rich, the 'plain' rich, the 'poorest' rich... and everyone else"[2].