Page 381 - Invited Paper Session (IPS) - Volume 2

IPS280 Erniel B. Barrios et al.
Model-assisted estimation using panel data
and data from independent samples for the
Philippine Family Income and Expenditure
survey
1
Erniel B. Barrios , Divina Gracia L. del Prado , Mae Abigail C. Oberos , Desiree
2
2
2
Robles , Jo Louise Buhay
2
1 School of Statistics, University of the Philippines
2 Statistical Methodology Unit, Philippine Statistics Authority

Abstract
The domains for the Philippine Family Income and Expenditure Survey (FIES)
are the regions. Design-unbiased estimation for the provinces (smaller areas)
would necessitate an increase the sample size to about four times. Considering
further that FIES is conducted semi-annually (at the end of reference
semester), using the same sample households for the survey year and
administered with a lengthy questionnaire, response burden and refusals
increases along with problems with willingness of interviewers to complete the
task for the entire survey duration. This problem is addressed by keeping the
regions as survey domains but partially rotating the samples in the two rounds
of data collection. This study then proposes a model-assisted estimation
procedure in combining panel data and data from independent samples to
generate annual estimates at the provincial level. Simulation studies indicate
the advantages of model-assisted estimation procedure over design-unbiased
method in generating estimates at the provincial level. Furthermore, sample
size requirement using model-assisted approach is only about half of the
required sample size for the design-unbiased method for reliable provincial
level estimates.

Keywords
Rotated sample; skewed population; cut-off sampling

1. Introduction
Nationwide surveys intended to generate official statistics often incur huge
cost and complex logistical issues in survey operations, hence, often constraint
statistical organizations to consider bigger areas (in some cases, national) as
the domains. However, more granular data is also needed to monitor progress
among countries towards achievement of sustainable development goals. The
Philippine Family Income and Expenditure Survey (FIES) is the source of many
indicators for various goals, the most important of which are poverty-related
indicators. FIES has always been a panel survey where same households are
visited every semester. While this has been observed to generate “reliable”
data for income and expenditures, it easily causes respondents’ fatigue

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