The two main reasons why Appraisal districts need to consistently assess all property at 100% of market value. The IAAO Standard suggests that residential properties have a coefficient of dispersion less than 15 percent. Property Tax Fiduciary 1.11. The Illinois 6, pp. Fundamental to the administration of the property tax is the concept that all property should be appraised and assessed on a uniform basis. Please review the necessary reporting forms and step-by-step instructions of the reappraisal process. A coefficient of dispersion (COD) not greater than 15.00%. Fourteen counties meet this standard. Reference: Bonett and Seier (2005), "Confidence interval for a coefficient of dispersion in nonnormal distributions", Biometrical Journal, Vol. Fundamental to the administration of the property tax is the concept that all property should be appraised and assessed on a uniform basis. Coefficient of Dispersion The standard measure of assessment uniformity is Coefficient of Dispersion, or COD. Coefficient of Dispersion - The relative dispersion or variability of assessments from the median. 144-148. Washington Department of Revenue Property Tax Division Annual Valuation Team (360) 534-1362 10/02/12 4 The coefficient of dispersion (COD) is the most used measure of uniformity in ratio studies, and the only other one we will be discussing today. Equity - Is measured by the coefficient of dispersion (COD). For improved residential property, it should be 0=<15%. 1-12. The Kansas Constitution requires that all taxable Counties with 50,000 or less inhabitants: Three year average of the median level of assessment – not more than 35.33% and not less than 31.33% of fair cash value of property within the assessment jurisdiction. Coefficient of variation is calculated by dividing the standard deviation by the mean or average ratio and multiplying by 100. Acceptable coefficients of dispersion depend on property type but should typically be 20% or less. The variance is What Is a Reappraisal? The IAAO suggested coefficient of dispersion for nonresidential property is 20 percent or less. Nineteen counties have coefficients of dispersion for residential properties greater than 15 percent. that result by the number of ratios. The COD should be 0=< on improved residential property and 0=<20% on all other classes. 48, pp. Applications: (See Property Tax Statistics, Sales Ratio and Equalization Tables.) 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