Comparing self-assessments using anchoring vignettes: an illustrated introduction
Discustant: Sabine Springer (FNG/INED)
Comparing self-assessments using anchoring vignettes: an
illustrated introduction
If the respondents to a cross-national survey use differently the
ordinal response categories to a self-assessment question, then
their responses need to be corrected before they can be compared.
In this talk, a correction method will be presented, which is based
on the appending of supplementary questions to the survey
questionnaire. Namely, the respondents are additionally asked,
during the survey, to provide assessments of imaginary situations,
called "anchoring vignettes", to which their self-assessments can
be compared. At the analytical stage, these "vignette assessments"
are used to detect comparability problems between samples or
populations, and to deal with possible Differential Item
Functioning effects in the respondents' self-assessments. The
proposed methodology will be illustrated using data from the Survey
on Health, Ageing, and Retirement in Europe 2004.
Do Danes and Italians Rate Life Satisfaction in the Same
Way? Using Vignettes to Correct for Individual-Specific Scale
Biase
Self-reported life satisfaction is highly heterogeneous across
similar countries. We show that this phenomenon can be largely
explained by the fact that individuals adopt different scales and
benchmarks in evaluating themselves. Using a cross sectional
dataset on individuals aged 50 and over in ten European countries,
we compare estimates from an Ordered Probit in which life
satisfaction scales are invariant across respondents with those
from a Hopit model in which vignettes are used to correct for
individual-specific scale biases. We find that variations in response
scales explain a large part of the differences found in raw data.
Moreover, the crosscountry ranking in life satisfaction
dramatically depends on scale biases.