“Subtract folks who owe more on their homes than they are worth and the home-ownership rate drops from 67% to 43%.”

Actually, of owner-occupied units, 38% are mortgage-free according to the most recent available data.
http://www.allcountries.org/uscensus/121 7_mortgage_characteristics_owner_occupie d_units.html

Thus, of that 67% a 38% share or 25% of all residences are owned free-and clear by the resident. Thus, 42% of all residences are owner-occupied and have a mortgage.
Thus, 24% of the 42% of homes with mortgages are underwater, or 10% of all residences.

Thus we have:
25% of residences owned-free and clear by the householder
32% of residences owned by householder, with a mortgage that is not underwater
10% of residences owned by a householder who is underwater
33% of householders rent

Thus, 57% and not 43% is the homeownership rate that you mean.

nice point to raise, on what constitutes ownership, for ownership definitely drivers behavior in terms of walk aways.

I wish more stats would show “ownership” on a debt equity basis like you mention.