What would really be interesting to see is what is driving that data, i.e. are the % reductions, duration to reduction, and probability of additional reductions driven by the actual innate ability to sell a house in zip X vs. zip Y, or are they driven by the relative owner's ability to wait longer for a better price?

I'd think it's the latter. Unfortunately, this creates a natural disparity in home prices between two such zip codes in that owners in lower income areas end up having to drop their home price in larger proportion to get their house sold, deflating aggregate prices in their zip. Higher value areas, while taking longer to sell the homes see a slower deflation of aggregate prices because of their ability to carry the costs longer.

Paying $5K a year in taxes on our Mt. Vernon condo relative to the $2K we'd be paying in AA county (given the rates you mentioned above) creates an immense gap in purchasing power, favoring county living.

The concept of lowering property taxes would have short term negative impacts to city revenue, but in reducing the purchasing power disparity vs. living in the county could have significant long term positive impacts to not only city housing prices, but also the cities income generation and overall economic well being.

I promise ... I did not set out to write such a long, nerdy, economic rant ... it just happened :-)

It seems that when some people talk about the high taxes we pay in the city vs. surrounding jurisdictions (i.e., adjoining counties), they do not seem to understand that they are not necessarily comparing apples to apples.
Urban areas, by their very nature have considerably more infrastructure and amenities to pay for. Such amenities are often a factor in where we decide to live and the related lifestyles we wish to pursue.

The infrastructure of urban environments is much more complicated and expensive to maintain than the same in suburban and rural areas. There are more sidewalks,
streetlights, libraries (at least a larger system in the city), three HUGE water reservoir systems, aging water and sewar systems, older, historic (albeit, costly to maintain) buildings, etc. Due to the urban grid, street repairs are costly. There are large police and fire departments, as well as a huge court system and related incarceration expenses. The city maintains lovely parks and a wonderful zoo. Further, the city incurs the added expense of human services since people from rural and suburban areas who require these services find a city more accomodating (accessible health care clinics, shelters, etc).

Still something to consider is that a key feature of living in the city is the fact that residents can typically walk or bike - or have shorter drives - to jobs, services, entertainment and recreation. The savings in gas alone (especially as we can expect the continued rise and volitility in oil prices as the essential commodity is rapidly being depleted) probably covers the cost difference alone. (And, please all this is not to say I particularly LIKE paying high taxes; it's just that you get what you pay for.)

Joan, the city limits encompass a larger area than just downtown. Homeowners closer to the county lines are generally screwed by the high tax rate. We aren't saving any gas.

Not all of us have the luxury of walking from our Harbor East Penthouses to CNE or Legg Mason.

Then again, the argument for lowering taxes is to increase the desire to live in the city limits, thus increasing tax revenue for the city by having more taxable incomes and homes.

If the rates aren't lowered to a respectable level, count on more people moving from the city to the county or even another state. This will add more strain to the the city's already crumbling tax revenue.