A grid-based sample design framework for household surveys

Abstract

Traditional sample designs for household surveys are contingent upon the availability of a representative primary sampling frame. This is defined using enumeration units and population counts retrieved from decennial national censuses that can become rapidly inaccurate in highly dynamic demographic settings. To tackle the need for representative sampling frames, we propose an original grid-based sample design framework introducing essential concepts of spatial sampling in household surveys. In this framework, the sampling frame is defined based on gridded population estimates and formalized as a bi-dimensional random field, characterized by spatial trends, spatial autocorrelation, and stratification. The sampling design reflects the characteristics of the random field by combining contextual stratification and proportional to population size sampling. A nonparametric estimator is applied to evaluate the sampling design and inform sample size estimation. We demonstrate an application of the proposed framework through a case study developed in two provinces located in the western part of the Democratic Republic of the Congo. We define a sampling frame consisting of settled cells with associated population estimates. We then perform a contextual stratification by applying a principal component analysis (PCA) and k-means clustering to a set of gridded geospatial covariates, and sample settled cells proportionally to population size. Lastly, we evaluate the sampling design by contrasting the empirical cumulative distribution function for the entire population of interest and its weighted counterpart across different sample sizes and identify an adequate sample size using the Kolmogorov-Smirnov distance between the two functions. The results of the case study underscore the strengths and limitations of the proposed grid-based sample design framework and foster further research into the application of spatial sampling concepts in household surveys.

Intercensal Updating Using Structure-Preserving Methods and Satellite Imagery

“…The United Nations (UN) recommends using satellite imagery to prioritize and check geospatial processes such as the delineation of enumeration areas during census preparation (United Nations Department of Economic and Social Affairs, 2009). It further supports the construction of population grids as a common spatial reference system as proposed by Stevens et al (2015), Freire et al (2016) and Boo et al (2020).…”

Intercensal updating using structure-preserving methods and satellite imagery

“…The United Nations (UN) recommends using satellite imagery to prioritize and check geospatial processes such as the delineation of enumeration areas during census preparation (United Nations Department of Economic and Social Affairs (2009)). It further supports the construction of population grids as a common spatial reference system as proposed by Stevens et al (2015); Freire et al (2016); Boo et al (2020).…”

High-resolution population estimation using household survey data and building footprints

“…together with measures of model uncertainty. The model leveraged household survey data with a probabilistic sampling design 17 , typically adopted in national household surveys, such as Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) 18 . Given that this type of design oversamples locations with higher population densities, we included a weighted-precision approach to recover unbiased estimates of population totals and densities with robust credible intervals 19 .…”