The big spread between the two companies' estimates are national, not just local. Zillow, a real estate site, says it worked with credit bureau TransUnion to get the exact loan balance for mortgaged homes -- including home equity lines -- so it didn't have to start with the original loan balance and estimate the amount paid off.
Both companies estimate home values, Zillow with its Zestimate.
Nationally, Zillow says 31 percent of mortgaged homes were underwater during the first three months of the year, same as its estimate for the Baltimore metro area. Within the region, negative equity varied dramatically, from more than half in a handful of Baltimore and Baltimore County ZIP codes to less than 10 percent in some of the pricey suburbs.
Zillow has an interactive map here.
These are the extremes:
21205 (area around the Johns Hopkins Hospital in East Baltimore), 53 percent
21202 (from the Inner Harbor in Baltimore to North Avenue), 52 percent
21230 (from Locust Point on the west to the city line on the east in Baltimore), 52 percent
21213 (just north of 21205 in East Baltimore), 52 percent
21223 (the Union Square area of Baltimore), 51 percent
(The only other ZIP code over the halfway mark is 21244, Windsor Mill in Baltimore County, at nearly 51 percent.)
21036 (Dayton in Howard County), 8.6 percent
21042 (Ellicott City in Howard County), 9.1 percent
21051 (Fork in Baltimore County), 9.6 percent
21405 (Annapolis in Anne Arundel County), 9.7 percent
21029 (Clarksville in Howard County), 9.8 percent
As you might expect based on those extremes, Baltimore has the highest overall share of underwater borrowers and Howard County has the least. Here's the negative-equity breakout by county, according to Zillow:
Baltimore: 46 percent of mortgaged homes underwater
Baltimore County: 33 percent
Anne Arundel County: 29 percent
Harford County: 27 percent
Carroll County: 23 percent
Howard County: 20 percent
Part of the reason for variations by area is that home prices haven't fallen the same amount everywhere. But it's not just that.
If Neighborhood A is full of people who moved in at least a decade ago and didn't borrow against their home value in the crazy days, it's going to have a lot less negative equity than Neighborhood B, built at the height of the housing bubble, or Neighborhood C, where half the residents moved in just before the crash and the other half did the home-as-ATM thing.
Zillow also estimated the extent of negative equity. On that count, the Baltimore area is doing a bit better than the nation as a whole: 45 percent of underwater borrowers here are underwater to the tune of 20 percent or less, compared with about 40 percent nationally.
And about 9 percent of underwater borrowers in the metro area owe more than double what their home is worth, Zillow estimated, compared with 15 percent nationally.
ZIP codes in the area with the most borrowers in that eye-popping over-double category:
21205 (23 percent)
21223 (19 percent)
21217 (16 percent)
21202 (15 percent)
21201 (13 percent)
They're all in Baltimore, and three are also on the most-underwater list above.
Are you underwater? By how much, if you could bring yourself to try to calculate it?
Economists have warned that the more underwater someone is, the more likely they'll call it a bad deal and just walk away from the home and mortgage. So far, though, most of the underwater crowd is paying, or at least isn't far behind.
Zillow says 11 percent of Baltimore-area borrowers with negative equity are more than three months delinquent.
TransUnion, by the way, isn't handing over homeowners' loan balances in a way that allows Zillow execs to see how much we all owe. Zillow says it shipped over its Zestimates and TransUnion sent back data that stripped the addresses, leaving just the ZIP code.
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