N.Y. Comp. Codes R. & Regs. tit. 12, § 308.2 – Calculating cost of compensation.

(a) The cost of compensation shall be calculated as follows:
1. (1) except as provided in subdivision (c) of this section, every $100 of payroll by employment classification multiplied by the highest rate approved by the Insurance Department for such employment classification for the period that the employer failed to make the provision for payment of compensation required by Workers' Compensation Law, section 50; plus
2. (2) the New York State assessments, calculated by multiplying the final result of the calculation in paragraph (1) of this subdivision by the assessment percentage determined by the New York Workers' Compensation Rating Board in effect on the date the penalty is calculated.
(b) In the absence of business records sufficient to determine the amount of payroll necessary to calculate the penalty, the amount of payroll shall be determined as follows:
1. (1) the New York State average weekly wage, as defined in Workers' Compensation Law, section 2(16), and reported by the Commissioner of Labor to the Superintendent of Insurance, in effect as of the date of the penalty; multiplied by;
2. (2) one and one-half times; multiplied by;
3. (3) the number of weeks in the period of noncompliance, rounded down to the nearest week; multiplied by;
4. (4) the number of employees, as determined by the chair, or his or her designee, after his or her investigation.
(c) If the Department of Insurance approves per capita premium rates for domestic workers employment classifications then the highest per capita rate will be substituted in place of payroll.
(d) The rates and domestic per capita rates in effect as of the date of penalty will be used for the entire noncompliance period, even if different rates were in effect during an earlier part of that period.