LogFAQs > #979611626

Basically:

• "Own" a home (usually via mortgate, unless you're old and paid it off)
• Salary ~ 3x or more the poverty level (what that is varies depending on if you're single, married, or a family), but still below the top 5% of income
• Have health care coverage
• Have some sort of retirement plan besides social security (pension, 401K, IRA, something...)
• Have at least 2 months of emergency savings in the bank

I don't know, I'd define it like that. You could add a bunch of implied societal stuff like being a nuclear family or going on vacation annually, but I tried to limit it to just economic situation stuff.