GDP Data Ratings

GDP per Capita Data Quality Ratings

World Economics Research Programme
31 January 2020

Major differences exist in the quality of both GDP and population data between countries. When GDP and population data of poor quality are combined to produce GDP per capita data the accuracy of the resulting ratio is further diminished. Significant variations in the quality of both GDP and population data compounds the problems in assessing the accuracy of measurements of GDP/capita which is the proxy means used for measuring living standards across countries. 

World Economics measures variation in the quality of both GDP and population data, by the Population Data Quality Ratings (PDQR) and the GDP Data Quality Ratings (GDP DQR) respectively and employs both scores to assess the overall accuracy of GDP per capita data. In most cases, because of out of date base years, a lack of resources in national statistics offices and a large unrecorded informal economy, official GDP figures are underestimates of actual economic activity, although in some rarer cases GDP may be overestimated as a result of government interference. 

Population data is most likely to be underestimated because of gaps between census years, low statistical capacity, high fertility and declining mortality rates and low rates of registration of birth particularly in many African and Asian countries. On the other hand there are also cases when a country’s population is overestimated and even census data can be highly politicised and distorted. For example, in Nigeria, many of the 36 constituent states over claim population size to gain bigger subventions from the Federal authorities or political power. In order to maintain their relative power position each state managed implausibly to maintain its