By millionaire, do we mean liquid assets or net worth? And do we only count individuals, or does household wealth qualify? Because if we take the latter in bot

By millionaire, do we mean liquid assets or net worth? And do we only count individuals, or does household wealth qualify? Because if we take the latter in both cases, a couple with decent white collar jobs, conservative spending, and maximized tax advantaged investments should make the cut inside a decade. It's boring but not difficult.