United Nations Regional Workshop on the 2010 World Programme on Population and Housing Censuses: Census Evaluation and Post Enumeration Surveys Addis Ababa, 14-18 September, 2009 By Deric Zanera Chief Statistician, National Statistical Office Malawi

Back ground Malawi conducted 4 post Enumeration Census 1966, 1977, 1987 , 1998 and 2008 PES has never been conducted in all these censuses Hence reliance on Demographic analysis as an ideal method for census evaluation

Evaluation Method Choice depends on ; the evaluation objectives availability of national skills and experience Availability of resources Adequacy of preparedness Lack of resources forced NSO to abandon well advance PES preparations

Demographic Analysis The NSO shall review several demographic techniques including the following; Visual inspection of census data Comparative analysis of two census age distributions. The basic procedure for assessing census quality on age-sex shall be through graphical analysis of population pyramid. Age-heaping or tendency of respondents to report a particular ending digit is a useful internal consistency check   Summary indices of Whipple's Index and Myer's Blended Index are the main tools for judging age-heaping. Stable population theory shall also be used to assess the quality of census distributions by age and sex. Measuring shall be on reported age-sex distribution against that of an appropri­ately chosen stable population.

conclusion The NSO is aware that the methods mentioned above, cannot differentiate the sources of census error in terms of the relative contributions from under-coverage (or over-coverage) or content error. Better information about coverage error through demographic analysis, derives chiefly from comparative analysis of data from successive censuses, in which all methods shall be used, namely:   (a) derivation of an expected population estimate taking account of vital registers of births, deaths and net migrants between censuses, as compared with the latest census, (b) Population projections based on the results of the prior census plus data on fertility, mortality and migration from various sources and comparing the projected estimates with the new census results (cohort component method), (c) Comparison of two census age distributions based on intercen­sal cohort survival rates and (d) Estimates of coverage correction factors using regression methods to make the age results from the two censuses mutually consistent.

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