§ 307. Computation of benefits. Compensation of a civil defense volunteer under this article shall be computed on the basis of his wages during the year preceding injury, in case of disability under the provisions of section fourteen subject to the limitations of section fifteen subdivision six, and in case of death under the provisions of section sixteen subdivision five; and "wages" shall be as defined in section two subdivision nine.

Compensation of a civil defense volunteer who was self-employed at the time of injury shall be computed, whether for disability or death, on the basis of the wages of a similar worker determined under the provisions of section fourteen unless the self-employed volunteer, or a dependent in a death case, shall authorize the state commissioner of taxation and finance to furnish to the chairman a copy of the income tax return of the civil defense volunteer filed to report income of the year next preceding the date of injury, in which event compensation under this article shall be computed on the basis of an assumed wage which shall be deemed to be the entire net income from self-employment minus investment income as reported to the state department of taxation and finance.

If earnings as so computed do not fairly represent normal earnings of the civil defense volunteer, there may be a redetermination more accurately to reflect earnings and the chairman may by rule prescribe reasonable procedures for such redetermination.

If the compensation of a civil defense volunteer can not be computed either on the basis of actual wages or wages of a similar worker, the compensation of such civil defense volunteer shall be at the rate provided in section fifteen subdivision six as the minimum rate for disability or, in case of death, on the basis of assumed wages which shall be deemed not to be less than the minimum provided in section sixteen subdivision five.