Over the last three decades the supply of economic statistics has vastly improved. Unfortunately, statistics on regional price levels (sub-national purchasing power parities) have been exempt from this positive trend, even though they are indispensable for meaningful spatial comparisons of...

The present paper shows that product-specific regional price dispersion usually causes the Country-Product-Dummy (CPD) method to be biased. In cases where it is not, this index number method is still inefficient and inference is invalid. In view of this, a nonlinear generalization of the CPD...