Organisations of many kinds use GDP data. Governments, Non-Governmental Organisations, Civil Societies, Businesses and a thousand others trust "official" economic data and use it as if it were holy writ. Highly regarded companies like global consultants McKinsey produce lists of the fastest growing countries to admire and perhaps invest in. Government aid is distributed, product plans put together, and factories built using such data as authoritative ammunition.
Yet few bother to inquire whether the GDP data used is of reasonable quality. In reality a great deal of GDP data is of such poor quality it should never be used to site an ice cream stall let alone be part of an elaborate business plan.
World Economics has spent many years studying the problems associated with GDP and population data. We have found many fault lines. Data is often out of date. Giant areas of economic activity not included. Half newly born children not registered. Statistics offices underfunded and unable to run good quality surveys. Data spoiled by politicians trying to gain an edge. Data simply not published to avoid political fallout. And so on.
World Economics has developed the Global GDP Data Quality Ratings to review the usefulness of official GDP data of individual countries. The Ratings currently cover five factors to determine data quality. Each factor is evaluated to provide country scores which are then normalised using the standard deviation of the data for each factor and combined into the DQR score using an average aggregate to reflect the importance of each of the individual factors. These five factors used to judge data quality are: Base Year used to calculate the GDP data (chained or years out of date), Standard of National Accounts (SNA) applied, estimated size of the Informal Economy, a proxy for Resources Devoted to Measuring Economic Activity and a proxy measure for likely Government Interference in Economic Data production. See expanded ranking table with source data.
The accuracy of population data varies widely across countries. In order to take account of the problems and to assess the relative accuracy of population estimates World Economics has produced a Population Data Quality Rating (PDQR). The ratings cover three factors: Census year, Statistical capacity and Registration of live births. See expanded ranking table with source data.