OUTLINE OF PRESENTATION

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European Conference on Quality in Survey
Statistics Q2006 City Hall, Cardiff, Wales,
United Kingdom 24 26 April 2006
Two step calibration in the presence of
nonresponse
Monica Pratesi, Emilia Rocco Università di Pisa,
Università di Firenze
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• Calibration and non response
• no model for non response process
• easy application

Lundström e Särndal 1999
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Calibration non response

• auxiliary variables
• administrative registers which variables?
• calibration constraint at which level?

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• Calibration and two phases sampling
• sampling weights known at each phase
• optimal combination of auxiliary variables and
  phases

Estevao e Särndal 2002
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Calibration non response

• step 1 sample selection
• sampling weights
• step 2 self-selection of respondents
• unknown weights

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• Two step calibration and non response
• optimal combination of phases and auxiliary
  variables ?

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• Final weights
• Calibration 1
• Calibration 2

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Outline of the presentation

• Auxiliary information
• Calibrated weights
• Bias and variance
• Simulation study
• Results and perspectives

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Auxiliary information
Study variable
Aux variable related to Y
Aux variable related to response process
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Auxiliary information
combinations

• 9 possible combinations of aux vars and two
  steps of calibration

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Simulation study study variable and aux vars

Särndal e Hui 1981
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Results
Case A
Case B
Case C
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Future research
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