The Times' investigative series on home prices in Hall County has opened eyes to some surprising disparities.

Our look at the value of homes assessed and sold in 2009, compared to that of previous years, shows home assessment values often are well off the selling price. Last year, homes sold for an average of 7.4 percent below their assessed value, two years after home sold for 9.5 percent more.

That upheaval serves as a microcosm of what has happened nationwide since the housing bubble burst in 2008. As more banks and financial institutions failed, burdened by bad loans papered over and swapped about as securities, homeowners and developers were faced with massive numbers of foreclosures.

Such was the case in Hall. There were 90 foreclosures out of more than 3,000 homes sold in 2005 and 45 out of 2,400 sales in 2008. Last year, there were 523 foreclosures out of only 994 overall sales. That spike has created a ripple effect throughout the housing market, driving average sale prices down.

Yet oddly enough, few Hall County residents have filed tax returns, just 350 out of 75,000 taxable properties, to begin the process of appealing their assessments. Tax appeals have increased markedly in neighboring counties, including Gwinnett and Forsyth.

It's important that residents are aware of how the process works and be willing to take action to change it. That's the only way the tax system can function properly for the benefit of all.

A bill sponsored by state Rep. Chip Rogers would give homeowners more power in the taxing process. It would offer homeowners a full 12-month window to appeal taxes, as opposed to the 30, 60 or 90 days they now have, depending on the county. There is room for compromise in that time window, but it's a positive step.

Other reforms would address how counties assess properties, seeking to create a more consistent standard that is fair to property owners. Rogers is negotiating with several different groups to refine the bill.

Because assessment and collection of property taxes is conducted at the city and county level, those officials also need to have input into whatever the legislature eventually passes.

Any reform needs to strike the right balance between the rights of homeowners to pay a fair property tax and the need for governments to have a consistent source of revenue to manage their budgets.

Keep in mind that property values and appraisals are only part of the tax equation. Taxes are determined by millage rates set by local elected officials. Higher or lower assessments don't automatically lead to higher or lower taxes. Taxpayers unhappy with what they pay have recourse, first in the appeal process, again at the ballot box.

Governments facing difficult budget choices understandably find themselves in a pickle. Money from Atlanta is drying up as state tax revenues have plummeted, forcing cities and counties to cut back on services and furlough workers. In this climate, it is tempting for officials to try and make up the difference when tax bills to go out.

A state law froze across-the-board tax assessments until 2012, meaning they can only assess individual properties. When that ban is lifted, counties should not try to make up for lost revenue by jacking up values across the board. If governments need to raise taxes, they should do it openly and honestly through the millage rate, not via the back-door means of raising assessments.

Once upon a time, counties reappraised properties in cycles, either all at one time every few years or on a staggered basis, some each year over a period of time. The data and technology exists today to eliminate that lag. Once the freeze period is lifted, every county in Georgia should be able to constantly update property values to keep them current.

The goal is to have assessments match, as closely as possible, the idea of a home's fair market value. But that concept is always going to be debatable. The relationship of "the market" and individual sales is a moving target. A motivated buyer may willingly pay too much for a home; a desperate seller may dump one too cheaply. The concept is one of averages and generalities, not precision. No one is ever going to get a tax bill and say "yes, by golly, that is exactly what my home is worth."

And many of those upset at paying higher taxes based on overvalued properties in the current market likely were more than willing to pay lower taxes during the real estate boom, when properties may have been undervalued.

Though the current upheaval in real estate has shown a brighter light on state law and the concept of fair market value, the debate over the current system of valuing property for tax purposes has been going on for years. Frequently debated proposals that suggest freezing property appraisals until a parcel is sold, then reappraising, are inherently flawed. They unfairly shift the tax burden to new property owners while giving indefensible tax breaks to folks who hold on to their property for a long time. The end result is the exact opposite of fair market value, but rather an outcome that means two identical houses sitting next to each other can have hugely different tax assessments.

Add the current rate of foreclosures to this mishmash and you have a housing market that doesn't know which end is up.

Eventually the economy will settle, foreclosures will slow to a crawl, the freeze on assessments will end and some kind of state reform for how property taxes are levied will be passed. For the sake of homeowners now and in the future, some long-term stability in how homes are taxed and sold would be welcomed.