


Definition: 
An effect which deprives a statistical result of representativeness by systematically distorting it, as distinct from a random error which may distort on any one occasion but balances out on the average.

Context: 
In the context of PPPs a bias is a systematic error in a PPP or volume index. Bias can arise for a number of reasons including failure to respect either representativity or comparability or consistency, the price collection and measurement procedures followed, and the calculation and aggregation formula employed.
Eurostat, OECD, 2007, EurostatOECD Methodological Manual on Purchasing Power Parities, OECD, Paris – Annex VII, Glossary of terms and abbreviations
The bias of an estimator is the difference between its mathematical expectation and the true value it estimates. In the case it is zero, the estimator is said to be unbiased.

Source
Publication: 
The International Statistical Institute, “The Oxford Dictionary of Statistical Terms”, edited by Yadolah Dodge, Oxford University Press, 2003.

Statistical
Theme: Methodological information (metadata) 
Glossary
Output Segments: 
SDMX

Created
on Tuesday, May 7, 2002 
Last
updated on Thursday, July 12, 2007 












