What is the primary difference between a de facto and a de jure census, and when would you prefer each approach?
ADe facto counts people at their usual residence; de jure counts them where they are on census night
BDe facto counts people where they are on census night; de jure counts them at their usual residence — de facto is simpler operationally but de jure is preferred for calculating demographic rates at the usual place of residence
CThere is no practical difference; both methods produce identical results
DDe facto only counts citizens; de jure counts all persons including non-citizens
De facto enumeration records people wherever they happen to be at the moment of enumeration — simple to implement because it avoids determining 'usual residence.' De jure enumeration assigns people to their usual place of residence, which is more useful for computing local demographic rates (since it matches people with the area where they normally live, work, and use services). The choice matters for populations with high mobility: de facto counts will over-represent tourist destinations and under-represent areas with temporary outmigration.
Question 2 True / False
Census under-coverage affects all demographic groups equally, so it does not bias demographic rates.
TTrue
FFalse
Answer: False
Census under-coverage is systematically biased by age, sex, race/ethnicity, socioeconomic status, and housing situation. Young men, racial minorities, homeless populations, and undocumented immigrants are consistently under-counted in most censuses. This differential under-coverage biases demographic rates: if the denominator (population) is too low for a group, rates derived from that denominator (death rates, birth rates) will be too high. Post-enumeration surveys allow statistical adjustment, but the corrections themselves carry uncertainty.
Question 3 Short Answer
Explain what a post-enumeration survey (PES) is and why it is considered essential to modern census practice.
Think about your answer, then reveal below.
Model answer: A post-enumeration survey (PES) is an independent survey conducted shortly after the census in a sample of areas, using a different enumeration team. It independently lists and interviews residents, then matches results against the census records to estimate how many people the census missed (under-coverage) and how many were counted more than once (over-coverage). The PES is essential because no census achieves perfect coverage, and the pattern of coverage errors is not random — it is systematically biased toward missing certain groups. Without a PES, users of census data cannot know the magnitude or direction of coverage errors, and demographic rates derived from census denominators may be misleading.
The dual-system estimation method used in PES applications is a demographic version of capture-recapture from ecology. The census is one 'capture' and the PES is another; the overlap between them estimates the total population. The method assumes independence between the two captures — an assumption that is never perfectly met but provides a workable approximation for coverage estimation.