2U.K.The model shall enable forecasts to be made—
(a)of any of the following, namely—
(i)the level of gross domestic product;
(ii)unemployment;
(iii)the balance of payments on current account;
(iv)the general index of retail prices; and
(v)average earnings; and
(b)of such (if any) other economic variables as are appropriate in the opinion of the Treasury from time to time.