What impact does the choice of formula have on international comparisons?

In this paper an empirical comparison of a number of alternative multilater al index-number formulae is undertaken. The magnitude of the effect of choo sing one formula over another is ascertained using an appropriate cross-sec tional data set constructed under the auspices of the Eurostat-OECD Purchas ing Power Parity Programme. To this end, a new indicator is proposed that f acilitates the measurement of the difference between two sets of bloc consu mption shares, each computed using a different multilateral comparison meth od.