39-1-104 (10.2) (a) (d) CRS Establishes the reappraisal cycle/data gathering period/appraisal date and concludes "said level of value shall be adjusted to the final day of the data gathering period."
For 2017, the gathering period is January 1, 2015, through June 30, 2016. This changes all raw sale prices, prior to June 30, 2016, to reflect the market value as of that date.
Time Adjustment Methodology
When price levels are changing significantly, sales prices must be adjusted for time. Separate time adjustment factors, by type of property and geographic area, may be necessary as rates of change in real estate prices often vary with these factors. Most appraisal organizations, such as the Appraisal Institute (Institute) and the International Association of Assessing Officers (IAAO), recognize the need for time adjustment (trending) of sales prices to the date of appraisal.
Determination of market adjustments for time involves the consideration of the four basic techniques of time trend analysis:
- Resale Analysis - the advantage of this technique is that it minimizes quality and location adjustments; however, characteristic changes between sales must be accounted for. The disadvantage of this method is the limited number of these types of sales.
- Paired Sales Analysis - This is a reliable method in areas where homes have minimal differences. This method works well in condominium complexes.
- Multiple Regression Analysis - This is a reliable tool for evaluation of the influence of several independent factors, such as property characteristics or time, on a dependent variable such as sale price.
- Sales Ratio Analysis - This reliable technique is efficient in that it inherently allows for large sample size. It does not require adjustment to the sales, in that it implicitly considers such factors by expressing sale price to assessed value, which should already reflect all relevant physical and location factors.