Section 1A. The commissioner, in addition to exercising the powers or performing the duties otherwise assigned to him, shall enforce all laws relating to the valuation, classification and assessment of property and shall supervise the administration of such laws by local assessors in accordance with the rules, regulations and guidelines established under the provisions of section one.

He shall determine whether or not the locally assessed values represent the full and fair cash valuation for each class of real property, as defined in section two A of chapter fifty-nine, and personal property not exempt from local taxation within each city and town. In each city and town which he has determined to be assessing at full and fair cash valuation, he shall determine a minimum residential factor for each city and town which shall be sixty-five per cent subject to such adjustment upward as may be required to provide that the percentage of the total tax levy imposed on any class of real or personal property shall not exceed one hundred fifty per cent of the full and fair cash valuation of the taxable property in said class divided by the full and fair cash valuation of all taxable real and personal property in the city or town. If adoption of said minimum residential factor would result in the residential property class bearing a higher percentage of the total property tax levy than the percentage of the total property tax levy imposed on the residential property class in the prior year, or if the adoption of said minimum residential factor would result in the residential property class bearing a higher percentage of the total property tax levy than the percentage of the total property tax levy imposed on the residential property class in the year prior to the year in which the minimum residential factor was first adopted, he shall determine a new minimum residential factor which shall be fifty per cent subject to an upward adjustment as may be required a) to provide that the percentage of the total tax levy imposed on any class of real or personal property shall not exceed one hundred and seventy-five per cent of the full and fair cash valuation of the taxable property of said class divided by the full and fair cash valuation of all taxable real and personal property in the city or town, or b) to provide that the adoption of said minimum residential factor shall not result in the residential property class bearing a lower percentage of the total property tax levy than the lowest percentage of the total property tax levy imposed on the residential property class in the years since he first certified that the locally assessed values represented the full and fair cash value. In no instance, however, shall the minimum residential factor, so determined, be greater than the amount of one hundred per cent, although a city or town may decide to adopt a residential factor greater than that amount. For this purpose, he may utilize the information on assessed values and classifications gathered pursuant to sections nine and ten and such other information as may be available to him. The taxable values and minimum residential factor so determined shall be sent to the individual cities and towns on or before April first of each year in which there is to be a determination of the percentages of the local tax levy to be borne by each class of property pursuant to section fifty-six of chapter forty.

In the performance of such duties, he may visit any city or town, inspect the work of its assessors and require of them any information he shall deem necessary regarding the procedures used in keeping records, maintaining tax maps and determining the valuation and classification for taxation of the property or any part thereof in such city or town. He shall require of them such action as will tend to produce uniformity within such city or town and throughout the commonwealth in the valuation, classification and assessment of property for local taxation.

He may require from state and town officers such returns and statements relative to the amount and value of taxable property in the several towns as he deems necessary. Information provided by said assessors shall include: (1) the total of all property subject to local taxation in each city and town, (2) the amount, if any, of tax abatements for the preceding year, and (3) such other information as may be required to aid the commissioner in the discharge of his responsibility in respect to the preparation of the equalization and apportionment report as provided in sections nine and ten.

He shall, at the request of the assessors of any city or town or upon his own initiative, give his opinion to assessors and collectors upon any question arising under any statute relating to the assessment, classification and collection of taxes or he may obtain the opinion of the attorney general upon such question. In either case, the opinion of the commissioner or the opinion of the attorney general, if any, shall be binding.

He shall issue, and may from time to time revise, a list of private firms or individuals qualified to perform appraisals or reappraisals of property for tax purposes in the commonwealth and shall make such list available to assessors. In any case where a city or town proposes to contract with any such private firm or individual for such appraisal or reappraisal services, such contract shall be with a firm or individual determined by the commissioner to be qualified to perform such services and said contract shall be approved as to form and content by the commissioner. Upon completion, he shall certify that valuations established under such appraisal or reappraisal of property for tax purposes by any such firm in the commonwealth comply with guidelines established under section one. Firms or individuals aggrieved by a decision of the commissioner that they are not qualified to perform appraisals or reappraisals of property for tax purposes in the commonwealth may appeal such decision to the appellate tax board.

He may cause an assessor to be prosecuted, either in the county where said officer resides or in an adjoining county, for any violation of law relative to assessment or classification of taxes for which a penalty is imposed. He may appear before any court or before any board of county commissioners sitting for the abatement of taxes, or before the appellate tax board.