This report is a collection of comments on the Read Paper of Fearnhead and
Prangle (2011), to appear in the Journal of the Royal Statistical Society
Series B, along with a reply from the authors.
Although approximate Bayesian computation (ABC) has become a popular
technique for performing parameter estimation when the likelihood functions are
analytically intractable there has not as yet been a complete investigation of
the theoretical properties of the resulting estimators. In this paper we give a
theoretical analysis of the asymptotic properties of ABC based parameter
estimators for hidden Markov models and show that ABC based estimators satisfy
asymptotically biased versions of the standard results in the statistical
literature.
Approximate Bayesian computation (ABC) is a popular technique for
approximating likelihoods and is often used in parameter estimation when the
likelihood functions are analytically intractable. Although the use of ABC is
widespread in many fields, there has been little investigation of the
theoretical properties of the resulting estimators. In this paper we give a
theoretical analysis of the asymptotic properties of ABC based maximum
likelihood parameter estimation for hidden Markov models.
We design a particle interpretation of Feynman-Kac measures on path spaces
based on a backward Markovian representation combined with a traditional mean
field particle interpretation of the flow of their final time marginals. In
contrast to traditional genealogical tree based models, these new particle
algorithms can be used to compute normalized additive functionals "on-the-fly"
as well as their limiting occupation measures with a given precision degree
that does not depend on the final time horizon.