"Switzerland's growth deficit: A real problem - but only half as bad as it looks." Available at http://www.snb.ch/d/download/referate/ref_050304_koh.pdf. BIS Review 77/2006  1  deflating GNP by the price index for domestic purchases rather than by the GDP deflator - the price of domestic output - it captures the terms-of-trade effect.
It is instructive to compare this measure of real income with that of GDP per capita over the past 35 years (Chart 1). While the two measures move broadly in sync for most of this extended period, they have diverged since 2003.