Is clustering the sample to the main urban centre biasing the sample to urban areas?
A validation study conducted in Peru showed that the sample is not biased to urban areas. In the study, the number of survey areas in the standard methodology was expanded both in number and in distance from the urban centre. At the time of the validation study the methodology included four survey areas: the main urban centre and three other administrative areas within one days travel from the main urban area. The validation study showed that increasing the number of survey areas, or increasing their distance from the main urban centre did not significantly affect the results obtained.
