Regional Price Parities and Real Regional Income for the United States

The success and expansion of the International Comparison Program (ICP) has led to an increase in interest and effort on the estimation of sub-national price levels and purchasing power parities (PPPs). The ICP highlighted a difficulty that large countries such as Brazil, Russia, India and China face during the price-collection phase, namely how to obtain average prices when there are large disparities in many types of expenditure categories, such as housing prices between rural and urban settings. The fact that such disparities were in evidence led to more research on within-country PPPs, or regional price parities (RPPs). The difference between a RPP and the PPPs is simply that the former are in the same currency, while PPPs are usually converted to a reference country or currency by the exchange rate, such as the United States Dollar or the Euro. This paper describes the methodology used to estimate the RPPs within the United States, and shows their effect on measures of income adjusted to constant dollars, termed real regional incomes.