What does a county assessor do?

The Imperial Palace in Tokyo: Worth a whole lot of yen.
The Imperial Palace in Tokyo: Worth a whole lot of yen.
Hiroshi Higuchi/Getty Images

In the 1980s, Japan experienced a major boom in its real estate market. As prices rose, the value of land exploded. At one point in 1989, the value of the grounds of the Japanese Imperial Palace in Tokyo was worth more than all of the real estate in California [source: Epstein].

The assessors in each of California's 58 counties at the time are the unsung heroes of that little tale. Without them, we wouldn't have the data that was compiled to find the total value of California's real estate. That's because county assessors in the United States are responsible for valuing every single piece of property in their counties.

Every few years -- usually three -- assessors estimate the value of each parcel of real property (with the general exception of schools, churches and charities) in the county. Real property is the combination of land and any structures on it. Every vacant lot, apartment complex, strip mall and home has a value; the assessor estimates that value based on the current real estate. In between these three-year pushes, the assessor identifies overlooked properties and locates and contacts the owners. The assessor also creates value assessments for new construction and determines whether any reassessment is in order when a property changes ownership.

The assessor compiles all of these property values into an assessment roll, which is a master list of the value of all the real property in a given county or jurisdiction.

The value estimates created by assessors take a number of factors into account, in addition to market values. For example, a new shed constructed in a homeowner's back yard will likely increase the value of the real property the year after it's built. Over time, however, the added value that shed brought to the property will decline as the shed ages and deteriorates.

There are two ways assessors can approach valuing real property. The first is the sales approach -- basing the value on the sale prices of similar structures and property in the area that have been sold recently. There's also the cost approach, which uses as a basis the cost of building a new similar structure on a similar piece of property and deducting any age or condition-related depreciation [source: State of Maryland].

What kind of madness would create a position that calls for such painstaking and thorough work? The answer is simple: taxes.

Assessing Property Taxes

The property taxes on a home are levied as a dollar amount per $100 or $1000 dollars of the home's value.
The property taxes on a home are levied as a dollar amount per $100 or $1000 dollars of the home's value.
Whit Preston/Getty Images

The point in creating the property value estimated by the assessor is to determine how much tax to levy against a property owner. Property taxes are usually of vital importance for the local government's budget. They pay for services like schools, law enforcement, fire and ambulance services, and parks. But how does an assessor calculate property taxes?

The most commonly used system of taxing is the rate system. On sales taxes, for example, the state collects an established, stable rate per dollar. So a one-dollar candy bar actually costs $1.07 in a state where the sales tax is 7 percent. The fluctuating amount the state collects through the sales tax depends on the dollar value of goods sold in the state that year.

This isn't the case with property taxes, which use a budget-based system of taxation. Under this system, legislators determine how much money their county will need to pay for the services that municipalities use property taxes to cover. When the legislators determine how much money will be needed, it's up to the tax assessor to divide the amount among the tax base -- in this case, the property owners in the county [source: Guppy].

The tax levied against real property is a percentage of the total tax amount legislators collect. So while the values of homes and businesses may change, the amount the county collects doesn't fluctuate based on these values; the property tax a homeowner pays does. When all property owners have paid the tax, the sum should equal the amount the legislators decreed should be levied against the county as a whole.

Usually the property tax is expressed in dollar amount per hundred or thousand dollars of a property's value. If the tax is one dollar per $100 of value, the property tax levied against a home valued at $108,000 will be $1,080 ($108,000 / $100 x $1) [source: State of Maryland].

You can see how fairness and accuracy are big parts of a county assessor's job. An overvalued home means a property owner will pay more than he or she really owes; undervaluing a property means that the county may fall short in its revenue projections.

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  • County of Santa Cruz. "What does the assessor do?" Accessed March 22, 2010.http://www.co.santa-cruz.ca.us/asr/asrresp.htm
  • Epstein, Edward Jay. "What was lost (and found) in Japan's lost decade?" Vanity Fair. February 17, 2009. http://www.vanityfair.com/online/daily/2009/02/what-was-lost-and-found-in-japans-lost-decade.html
  • Guppy, Paul. "Are your property taxes going up? Don't blame the tax assessor." June 26, 2002. http://www.kingcounty.gov/~/media/Assessor/News/OpEd6_26_02.ashx
  • Los Angeles County. "Real property assessments." Accessed March 22, 2010. http://assessor.lacounty.gov/extranet/Guides/realprop.aspx
  • Retirement Living Information Center. "Taxes by state." January 2010. http://retirementliving.com/RLtaxes.html
  • State of Maryland. "SDAT: homeowner's guide." July 27, 2009. http://www.dat.state.md.us/sdatweb/hog.html