18,787 research outputs found
A hierarchical Bayesian approach to record linkage and population size problems
We propose and illustrate a hierarchical Bayesian approach for matching
statistical records observed on different occasions. We show how this model can
be profitably adopted both in record linkage problems and in capture--recapture
setups, where the size of a finite population is the real object of interest.
There are at least two important differences between the proposed model-based
approach and the current practice in record linkage. First, the statistical
model is built up on the actually observed categorical variables and no
reduction (to 0--1 comparisons) of the available information takes place.
Second, the hierarchical structure of the model allows a two-way propagation of
the uncertainty between the parameter estimation step and the matching
procedure so that no plug-in estimates are used and the correct uncertainty is
accounted for both in estimating the population size and in performing the
record linkage. We illustrate and motivate our proposal through a real data
example and simulations.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS447 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Bayesian inference of natural selection from allele frequency time series
The advent of accessible ancient DNA technology now allows the direct
ascertainment of allele frequencies in ancestral populations, thereby enabling
the use of allele frequency time series to detect and estimate natural
selection. Such direct observations of allele frequency dynamics are expected
to be more powerful than inferences made using patterns of linked neutral
variation obtained from modern individuals. We develop a Bayesian method to
make use of allele frequency time series data and infer the parameters of
general diploid selection, along with allele age, in non-equilibrium
populations. We introduce a novel path augmentation approach, in which we use
Markov chain Monte Carlo to integrate over the space of allele frequency
trajectories consistent with the observed data. Using simulations, we show that
this approach has good power to estimate selection coefficients and allele age.
Moreover, when applying our approach to data on horse coat color, we find that
ignoring a relevant demographic history can significantly bias the results of
inference. Our approach is made available in a C++ software package.Comment: 27 page
Bayesian Estimation Under Informative Sampling
Bayesian analysis is increasingly popular for use in social science and other
application areas where the data are observations from an informative sample.
An informative sampling design leads to inclusion probabilities that are
correlated with the response variable of interest. Model inference performed on
the observed sample taken from the population will be biased for the population
generative model under informative sampling since the balance of information in
the sample data is different from that for the population. Typical approaches
to account for an informative sampling design under Bayesian estimation are
often difficult to implement because they require re-parameterization of the
hypothesized generating model, or focus on design, rather than model-based,
inference. We propose to construct a pseudo-posterior distribution that
utilizes sampling weights based on the marginal inclusion probabilities to
exponentiate the likelihood contribution of each sampled unit, which weights
the information in the sample back to the population. Our approach provides a
nearly automated estimation procedure applicable to any model specified by the
data analyst for the population and retains the population model
parameterization and posterior sampling geometry. We construct conditions on
known marginal and pairwise inclusion probabilities that define a class of
sampling designs where consistency of the pseudo posterior is
guaranteed. We demonstrate our method on an application concerning the Bureau
of Labor Statistics Job Openings and Labor Turnover Survey.Comment: 24 pages, 3 figure
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