Variance estimation under monotone non-response for a panel survey
Section 4. Longitudinal estimators
We may be interested in a change in parameters, such as
the difference between the totals of a variable of interest measured at
two different times
Since the variable
is measured on all sub-samples
for
there are several possible estimators for
For
we denote by
the estimator which makes use of
for the estimation of
and of
for the estimation of
The case
corresponds to the estimation of
on the largest available sub-sample,
The case
corresponds to the estimation of
and
on the common sub-sample
In the context of full response, several authors have
recommended the estimator
which makes use of the common sample only, if
the variables
and
are strongly positively correlated; see Caron
and Ravalet (2000), Qualité and Tillé (2008), Goga, Deville and Ruiz-Gazen (2009),
Chauvet and Goga (2018).
In our context, this choice may be heuristically justified as follows. For
and by conditioning on the sub-sample
we obtain
In equations (4.3) and (4.4), the first term in the right-hand side is
identical. Since the variables
and
are expected to be positively correlated, the
difference
is expected to be smaller than
Therefore, the estimator
based on the common sample is expected to be
more efficient in terms of variance. The results of a small simulation study in
Section 5.2 support this heuristic reasoning. Therefore, we focus only in
this Section on the estimator
for the estimation of
As pointed out by a Referee, and following the
approach in Zhou and Kim (2012), we may obtain a gain in efficiency by using the full
information on
namely by calibrating the weights
on the estimator
Replacing in (2.11) the variable
with
yields the estimator of the variance due to
the sampling design
Similarly, replacing in (2.12) the variable
with
yields the estimator of the variance due to
the non-response
with
The global variance estimator for
is
Variance estimation for measures of change is also considered in Berger (2004),
Qualité and Tillé (2008), Goga et al. (2009), Chauvet and Goga (2018), among others.
The simplified estimator of the variance due to
non-response is
If the variables
and
are strongly positively correlated, the bias
of the simplified variance estimator is expected to be small.
ISSN : 1492-0921
Editorial policy
Survey Methodology publishes articles dealing with various aspects of statistical development relevant to a statistical agency, such as design issues in the context of practical constraints, use of different data sources and collection techniques, total survey error, survey evaluation, research in survey methodology, time series analysis, seasonal adjustment, demographic studies, data integration, estimation and data analysis methods, and general survey systems development. The emphasis is placed on the development and evaluation of specific methodologies as applied to data collection or the data themselves. All papers will be refereed. However, the authors retain full responsibility for the contents of their papers and opinions expressed are not necessarily those of the Editorial Board or of Statistics Canada.
Submission of Manuscripts
Survey Methodology is published twice a year in electronic format. Authors are invited to submit their articles in English or French in electronic form, preferably in Word to the Editor, (statcan.smj-rte.statcan@canada.ca, Statistics Canada, 150 Tunney’s Pasture Driveway, Ottawa, Ontario, Canada, K1A 0T6). For formatting instructions, please see the guidelines provided in the journal and on the web site (www.statcan.gc.ca/SurveyMethodology).
Note of appreciation
Canada owes the success of its statistical system to a long-standing partnership between Statistics Canada, the citizens of Canada, its businesses, governments and other institutions. Accurate and timely statistical information could not be produced without their continued co-operation and goodwill.
Standards of service to the public
Statistics Canada is committed to serving its clients in a prompt, reliable and courteous manner. To this end, the Agency has developed standards of service which its employees observe in serving its clients.
Copyright
Published by authority of the Minister responsible for Statistics Canada.
© Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, 2018
Use of this publication is governed by the Statistics Canada Open Licence Agreement.
Catalogue No. 12-001-X
Frequency: Semi-annual
Ottawa