IT_t: Imputation Tornqvist (GEKS-IT), also known as the ITRYGEKS (Imputation
Tornqvist Rolling Year GEKS)
Description
The GEKS-IT is a variation of the GEKS that uses a bilateral 'imputation Tornqvist'
(regression based) index for all bilateral index calculations.
Usage
IT_t(p0, p1, q0, q1, f0, f1, id0, id1)