The article discusses three principal methods for estimating depreciation: (1) the market extraction method, (2) the economic age-life method, and (3) the breakdown method. It further discusses how these methods are applied in Ontario, Canada.
Stadig, M. (2011). Estimating depreciation for property assessment purposes. Journal of Property Tax Assessment & Administration, 8(4), 5-13. Retrieved from https://researchexchange.iaao.org/jptaa/vol8/iss4/1