Subject to paragraph (3), there shall be paid to a State an amount equal to 100 percent of the amount of short-time compensation paid under a short-time compensation program (as defined in section 3306(v) of title 26) under the provisions of the State law.

Payments made to a State under paragraph (1) shall be payable by way of reimbursement in such amounts as the Secretary estimates the State will be entitled to receive under this section for each calendar month, reduced or increased, as the case may be, by any amount by which the Secretary finds that the Secretary’s estimates for any prior calendar month were greater or less than the amounts which should have been paid to the State. Such estimates may be made on the basis of such statistical, sampling, or other method as may be agreed upon by the Secretary and the State agency of the State involved.