As well, I'm curious about how "Household Income" is defined. Does "income" include workplace benefits that have been increasingly chipped away in recent years? If not, then it's not really an apples to apples comparison. If a job that paid $40k inflation-adjusted dollars 20 years ago pays $44k now, but no longer comes with a pension plan and benefits package, is isn't reasonable to say that income from that job has increase by 10%.
-k
Household income does not include workplace benefits. It includes literally those things that go into household income on your tax forms (pay, pension payments, disability, etc.).