I agree with the main point of the article -- Americans were supporting lifestyles with borrowing. As we get into a recovery, if they don't borrow as much as they used to (either due to new consumer caution, or new lender caution), we should expect the recovery to be slow.
But, his median family numbers are questionable.
As already mentioned, he overstates FIT by nearly $10,000. (I got a taxable income of $46,376, taxes before child credit of $6,154, and taxes after child credit of $4,154.)
I'd also expect most families with new mortgages to be spending closer to 25% of gross income on principle, interest, taxes, and insurance. That would be $18,000 instead of his $12,000. His housing expense is surprisingly low.
A more interesting point is that this family doesn't "need" to save a lot for retirement. If they work to the SS normal retirement age, their annual SS benefit will be close to $29,000. When I take their income, subtract FIT, SS tax, Medicare tax, FIT, mortgage, and 1/2 the cost of food, cars, and miscellaneous (keeping 100% of the cost of utilities, RE tax, and inserting Medicare part B for medical), I have a retirement budget of just about $29,000.
Of course, I don't have the rest of their medical expenses, and SS probably won't pay the full amount. Yet, nearly 60% of their current income is being spent on things that would go away in retirement, so they can rationally target a replacement ratio way below 70%.
(p.s. The author could have found out what American families actually spend by checking the Consumer Expenditure Survey.)