The present volume provides a timely collection of material on the subject of international comparisons, contributed by leading scholars from an extensive range of relevant disciplines and geographical backgrounds. The papers in this volume have been classified into two broad groups united by overlapping themes. Part I includes essentially empirical papers intended to provide a clear picture of the different types of international comparisons that have been undertaken by various organizations and individuals. The papers relate to empirical studies of different sectoral and national income aggregates at both regional and global levels. The papers in Part II deal with methodological and analytical issues. Discussion of the appropriateness of various aggregation methods for international comparisons accounts for a major component of this section. The volume provides a set of stimulating studies on international comparisons of prices, output and productivity, and will provide a useful reference source for many interested readers around the world.

Economists wish to compare prices, real income, and output across countries and regions for many purposes. In the past, such comparisons were made in nominal terms, or by using exchange rates across countries, ignoring differences in price levels and thus distorting the results. Great progress has been made in interspatial comparisons in the past thirty years, but descriptions and discussions of the new measures have been scattered in unpublished or inaccessible papers. International and Interarea Comparisons of Income, Output, and Prices includes discussions of developments in the United Nations International Comparison Program, the largest effort in this field, and in the ICOP program on the production side, including efforts in both to extend the comparisons to the formerly planned economies. Other papers in this volume explore new programs on interspatial comparisons within the United States. There are also theoretical papers on how interspatial comparisons should be made and several examples of uses of such comparisons.

The International Comparison Program (ICP) is a worldwide statistical initiative led by the World Bank under the auspices of the United Nations Statistical Commission. It produces comparable price and volume measures of gross domestic product (GDP) and its expenditure aggregates across economies. Through a partnership with international, regional, sub-regional and national agencies, the ICP collects price data and GDP expenditures to estimate purchasing power parities (PPPs) for the world’s economies. The report provides ICP results for the benchmark year 2017 and revised results for earlier years. ICP data are used for socio-economic analyses by researchers, academics, policy makers at the national and international levels, and by organizations such as the European Union, the International Monetary Fund, the Organization for Economic Co-operation and Development, the United Nations, and the World Bank. Notably, PPPs and ICP data are used in indicators monitoring progress towards eight goals of the United Nations’ 2030 Agenda for Sustainable Development, the World Bank’s international poverty lines, and the construction of the Human Development Index by the United Nations, among others. The use of PPPs continues to grow and the ICP website (icp.worldbank.org) lists many applications of the data by the development community, academia, media and others.