See: Net Debt. See: Net Debt Per Capita.
This term carries the same notion. It's net debt, not total debt that we care about. If a country had a trillion dollars in debt, but like 900 billion dollars in cash, then they have net debt of $100 billion. Same deal with corporations, although with smaller numbers. But not much smaller in some cases. Hi, Apple.
Anyway, a given entity might have an assessed valuation of $20 million. Think: 4,000 acres of land that has a lot of oil on it...probably. That land also has $12 million in debt and $4 million in cash in its little Acre of the Wood bank account. So it has net debt of $8 million divided by its assessed valuation of $20 million, or 8/20 = 2/5, or 40% net debt to assessed valuation.
Why do we care about this calculation? Well, if the net debt was more than the assessed value of the property, then the banks own it. That is, the assessed value is low relative to the debt, so the bank or whoever loaned the money just hopes to get their dough back, or as much of it as possible once the property is sold. #LickWounds.