4 research outputs found
Bias correction in multiple-systems estimation
If part of a population is hidden but two or more sources are available that
each cover parts of this population, dual- or multiple-system(s) estimation can
be applied to estimate this population. For this it is common to use the
log-linear model, estimated with maximum likelihood. These maximum likelihood
estimates are based on a non-linear model and therefore suffer from
finite-sample bias, which can be substantial in case of small samples or a
small population size. This problem was recognised by Chapman, who derived an
estimator with good small sample properties in case of two available sources.
However, he did not derive an estimator for more than two sources. We propose
an estimator that is an extension of Chapman's estimator to three or more
sources and compare this estimator with other bias-reduced estimators in a
simulation study. The proposed estimator performs well, and much better than
the other estimators. A real data example on homelessness in the Netherlands
shows that our proposed model can make a substantial difference
Risso's dolphins alter daily resting pattern in response to whale watching at the Azores
Peer reviewedPreprin
Bias correction in multiple-systems estimation
If part of a population is hidden but two or more sources are available that each cover parts of this population, dual- or multiple-system(s) estimation can be applied to estimate this population. For this it is common to use the log-linear model, estimated with maximum likelihood. These maximum likelihood estimates are based on a non-linear model and therefore suffer from finite-sample bias, which can be substantial in case of small samples or a small population size. This problem was recognised by Chapman, who derived an estimator with good small sample properties in case of two available sources. However, he did not derive an estimator for more than two sources. We propose an estimator that is an extension of Chapman's estimator to three or more sources and compare this estimator with other bias-reduced estimators in a simulation study. The proposed estimator performs well, and much better than the other estimators. A real data example on homelessness in the Netherlands shows that our proposed model can make a substantial difference