What is Equalization?

Legal Definition
The act or process of making equal or bringing about conformity to a common standard. The process of equalizing assessments or taxes, as performed by "boards of equalization" In various states, consists In comparing the assessments made by the local officers of the various counties or other taxing districts within the jurisdiction of the board and reducing them to a common and uniform basis, increasing or diminishing by such percentage as may be necessary, so as to bring about, within the entire territory affected, a uniform and equal ratio between the assessed value and the actual cash value of property.

The term is also applied to a similar process of leveling or adjusting the assessments of individual taxpayers, so that the property of one shall not be assessed at a higher (or lower) percentage of its market value than the property of another. See Harney v. Mitchell County, 44 Iowa, 203; Wallace v. Bullen, 6 Okl. 757, 54 Pac. 074; Poe v. Howell (N. M.) 67 Pac. 62; Chamberlain v. Walter, 6o Fed. 792; State v. Karr, 64 Neb. 514, 90 N. W. 298.
-- Black's Law Dictionary